The main goal of this paper is to analyse the connotation of 'regional innovation environment' and explore the relationships between the regional innovation environmental components and innovation efficiency (IE). Three regional environmental factors were extracted, namely, economic infrastructure (EI), the quality and structure of innovators (QSI) and regional openness (RO). The relationships between the regional innovation environmental components and innovation efficiency present a chain structure as RO–EI–QSI–IE. Only the QSI component affects IE directly, and all of the effects are positive. Based on these results, the characteristics of Chinese regional innovation systems were analysed, and the implications on science & technology policy were discussed.