Abstract: By examining collaborative invention patent applications from 1985 to 2015, this paper investigated the evolution of China’s inter-regional R&D collaboration patterns which was closely linked with the evolution of China’s S&T system reform. Based on the multidimensional proximities, this paper further identified the influence factors of China’s inter-regional R&D collaboration patterns in different periods, our results provided evidence that, the effect of geographical proximity was varied for different patterns and weakened by periods; the effect of technological proximity was varied in different periods, the most optimal level of technological proximity appeared in inter-regional collaboration between enterprises and academic institutions; the effect of relational proximity measured by the degree of previous collaboration was significantly positive, especially for inter-regional collaboration between enterprises and academic institutions, however, the effect of relational proximity measured by previous collaboration existed or not was varied for different patterns and in different periods; the effect of institutional proximity was significantly positive, especially for inter-regional collaboration between enterprises.