Abstract: Based on the cointegration theory, the dynamic equilibrium relationship between public R&D investment, technology innovations and rice productivity growth for China over the period of 1990-2006 in both long and short terms is demonstrated. The results show that there exist long-term unilateral Granger causality relationship in the presence of cointegration between public R&D investment and technology innovation, and the relationship either between technology innovation and TFP growth, or between public R&D investment and TFP growth is insigniticant. Moreover, Granger causality tests demonstrate that unilateral Granger causality exists between public R&D investment and the change of technology innovation, meanwhile between applied research investment and the change of TFP in the short term, however the change of technology innovation is still not the main reason that promotes TFP growth in the short run, and has no effect on the TFP growth. According to empirical results, relevant explanations are provided at last.