Few decades ago it would be considered as a joke but in the present conditions it could be considered as reality. According to Russian sources, cooperation with China in joint development of new super heavy launch vehicles, which could be utilized during Moon mission, is more than possible.
Both countries are developing own Moon exploration programs with ambitious goals. Russia is targeting for manned Moon missions and establishing lunar outpost in 2030s. China is planning further robotic exploration and creating large space station which will serve in future for Moon and deep space exploration. Of course China is not denying that they are targeting into manned mission to the Moon but still there is no timetable for this program. In spite of Moon landing, both countries are planning to establish own space stations and are possessing or developing heavy rockets able to deliver to orbit large payloads: Angara in heavy version (and Soyuz-FG at the moment) and Long March 5. Fact that cooperation of these two countries could bring positive results for both partners seems to be obvious, but until now, various propositions were rather given by Russia than China. Fact, that such cooperation was started, was unveiled by Anatoly Perminov, previous chief of the Roscosmos in 2006 along with declaration that joint Russian-Chinese Space Sub-Commission was working on appropriate agreement. Since 2006, Russia invited China many times for different kinds of cooperation in space, but without positive results. One of the key joint programs was Phobos-Grunt space probe which was built by Roscosmos with participation of CNSA. Unfortunately after launch on November 8, 2011, probe failed to start its journey from parking orbit to Phobos (one of the Martian moons). In 2012 probe burnt in Earth atmosphere with Chinese Martian orbital probe Yinghuo-1 onboard. This failed mission was in fact only serious space venture which appeared since 2006 as result of Sino-Russian cooperation. On April 2015 Russian Deputy Prime Minister Dmitry Rogozin announced about Russian proposition for starting cooperation with China for creating lunar base in near future (it was mentioned that it is possible to create base until end of 2020s). Unfortunately after meeting with Chinese Vice Premier Wang Yang later in 2015, proposition was still proposition and Chinese side seemed not to be interested in such cooperation.
On June 25, 2016 in Beijing Russian President Vladimir Putin met with Chinese President Xi Jinping, but in spite of fact that meeting was on highest level, Sino-Russian cooperation will not dramatically change after this meeting. Russian side of course is able to claim that it was great success; China still declares will of buying famous Russian Energomash RD-180 engines, but still there was more declaring than true action. Previous declarations by Andrey Denisov, Russian Ambassador in China, that cooperation for new heavy rocket and combining efforts to accelerate Moon programs of both countries is natural and seems to be undisputable, were premature. Ambassador even predicted cooperation in deep space exploration and colonization of Moon:
"In a perspective, cooperation is perceptible in the field of designing a heavy rocket and establishing interaction in the sphere of space stations and long-distance flights."
Chinese side apparently has other plans for own space exploration. Russia, which is strongly interested in selling arms and space technologies to China to cover hole in the budget caused by numbers of sanctions after Crimea crisis could consider this business as recessed comparing to previous decades. China developed own technologies and when in the early 2000s, Russian Soyuz spacecraft and Russian weapon were bought by China, now in fact China could sell to Russia own technology. Good example of change in Chinese space industry could be next generation Chinese spacecraft which capsule scaled model was successfully tested on June 26, 2016, which development seems to be more advanced comparing to Russian “Federation” spacecraft. Another example could be, recently announced by CALT (China Academy of Launch Vehicle Technologies), starting development of new rocket which will be able to lift payload five times heavier than present Long March rockets. With such launch vehicle, CNSA will be able to seriously consider deep space missions including sending heavy payload to Mars or delivering large payload to the Moon. CALT also declared that maiden flight of the rocket is possible in next 15 years. Russia probably would like to see inside next generation Chinese rockets Russian engines, but for the moment it seems less possible. Long March 7 which recently was successfully launched from Wenchang Satellite Launch Center was equipped with YF-100 Chinese made rocket engines which were designed independently by Xi'an Aerospace Propulsion Institute.
Russia also presented various propositions of participation in space medicine programs which could be useful for CNSA, especially due the ban for Chinese participation in International Space Station. According to Dmitry Rogozin Chinese side expressed "keen interest" in these projects but again without any clear declaration. At the moment Chinese space industry seems to be in very good condition. Various advanced projects like new generation of Long March rockets, successful development of next generation spacecraft, started program of new hypersonic plane which could be considered as the beginning of the creating reusable space plane, successes of the Chang'e lunar probe and advanced plans of creating own space station puts at the moment China in more favorable position comparing to Russian partner. Roscosmos with shrinking budget, postponed Moon program and very general plans for own space station are able to offer China engines, technologies and know-how, but still it is possible that space industry of China is strong enough to achieve same technologies independently sooner or later without involving in cooperation with potential competitor.
On picture above: Phobos-Grunt in 2011.