This paper investigates the combined role of innovation support policies and firm's own innovative activities on the performance of Chinese small- and medium-sized enterprises (SMEs) in high-tech sectors. By distinguishing two components of innovative activities—research and development (R&D) investments and embedded innovative capacity—the paper develops and tests an integrative moderated moderation model. The results suggest that in Chinese high-tech SMEs innovation-support policies positively moderate the relationship between R&D investments and performance, but this positive effect diminishes when there are higher levels of embedded innovative capacity. These results highlight that the relationship between government innovation policies and a firm's own R&D investments is not only reciprocal but also more complex than the one so far analyzed in the literature. The results show in particular that the effects of innovation-support policies on R&D investments is not as neat as it seems, because of the internal balance within the firm between investment in R&D and other sources of innovation. Therefore, although innovation support policies have been found to help Chinese SMEs in high-tech sectors benefit from their R&D investments, these policies are particularly effective only when R&D investments are significantly driving firms’ innovative activities. This highlights the relevance of both government support and a firm's own efforts in the competitive modernization of Chinese SMEs.