Abstract: Based on the data from 1206 manufacturing firms of Yangtze River Delta, this paper explores the relationships between factors of synergic innovation of firms and their synergic degree using the method of factor analysis and multiple regressions. The results show that: first, factors of synergic innovation of firms mainly include the main supporting factors, policy environmental factors, institutional factors, and social network factors; second, synergic degree of firms mainly include synergy mode, inter-firms synergy, firms-research institutions synergy, firms-university synergy, firms-intermediaries synergy, firms-government synergy, elements synergy, and spatial synergy; third, factors of synergic innovation of firms have positive impact on their synergy degree, and the environmental factors of policy have most significant impact on firms' multidimensional synergy degree.

Key words: synergic innovation, synergic degree, manufacturing firms