This paper presents an empirical analysis on the relationship between the size of Chinese government, as measured by its annual spending, and the growth rate of the economy. More specifically, it is designed to examine the applicability of Wagner's Law to the Chinese economy. The statistics used in this research are annual time series data on total government spending and gross domestic product covering the period of 1952 to 2007.Unexpectedly, our empirical results showed no strong evidence in support of the validity of the Wagner's Law for Chinese economy. However, our research shows a characteristic of smooth time-varying parameters for the relationship between Chinese government expenditures and growth rate of GDP.