Granger causality analyses aim to reveal the direction of influence between brain areas by analyzing temporal precedence: if a signal change in area A consistently precedes a signal change in area B, then A Granger-causes B. China is a country with a great quantity of automobile production and usage. With the rapid development of economy, the demand of our country's automobile is in a state of sustained growth. China is one of the fastest growing economies in the world, and the automobile production and sales volume has been ranked NO.1 in the world. The impact of China's automobile production and sales of internal factors has been widely concerned. Granger causality is the representative of the method which is the use of large sample data for a long period of time. The relationship between income and car sales is studied. But in fact, with the characteristics of different stages of the development of China's economy, the relationship between income and car sales is very different. Through the analysis of the causal relationship of the two, it can be more able to confirm the relation between the two. And through the inspection of the lag, considering the time lag, it makes the independent variable and dependent variable reaching the height of the fitting and it is conducive to analyze the causal relationship between dependent variables.