This paper discusses the history, scale, pattern of NGOs’ cooperation in the 20th century and its impact on the development of Sino-Russian relations. This article explores the following activities: the rights protecting activities of organizations for Overseas Chinese in Russia in early 20th century; cultural and educational activities of Overseas Russians in Harbin and Shanghai from 1920s till 1940s; activities in publicizing and researches of various research communities for the Soviet Union during the period of the Republic of China, all-around publicity by the Sino-Soviet Friendship Association during the new China period; a full range of bilateral trade and economic, cultural, educational, academic and other activities by Chinese and Russian NGOs since China’s reform and opening up policy. This article holds that there are two basic modes of cooperation for Chinese and Russian NGOs in the 20th century, namely, “NGO Cooperation” and “NGO plus Governmental Cooperation”. Regarding the cooperation scale, it was small like a trickle at the beginning of the 20th century; tided up in the 1950s, sunk to a low ebb in the 1960s; developed in multiple fields and at multiple levels since the 1990s. The content of the Sino-Russian cooperation in the 20th century was various and has become an important complement to bilateral relations---in the political field, launched the masses, implemented national policies and extended the country’s arms; in the economic and trade field, it depended on the mass power and temporarily excluded some barriers which the countries can not afford to take into account, becoming a great help to the country; in the cultural, science, and educational fields, it made use of the advantages of NGOs’ flexibility in decision-making and has become a go-between between the two countries. The cooperation of NGOs between China and Russia in the 20th century has become an important part of Sino-Russian relations. The cooperation potential between Chinese and Russian NGOs is great and can thus accomplish a lot.