The impact of wheat diversity on the productivity of wheat in China is examined using total factor productivity (TFP) and an instrumental variable approach. TFP in seven key wheat-producing provinces in China shows significant, though variable, growth for all provinces during the period 1982-1995. Analysis of the causes of TFP growth tests alternative taxonomies of wheat diversity (named varieties and morphological groups) and three measures of diversity. The analysis shows significant effects of diversity on TFP with results consistent across taxonomies and measures of diversity. Further decomposition of the estimation results confirms the relative magnitude of impact of wheat diversity on TFP growth.