Abstract: With the implementation of allowance for purchasing agricultural machinery in last ten years， the central government investment has been increasing， driving more and more investment from all aspects，especially from farmers. Therefore, it greatly increased the total power of agricultural machinery. Based on the panel data from provinces of China in 2000\|2012，the article estimated the quantity relations between the inputs for purchasing agricultural machinery and the growth of total power of agricultural machinery from 31 provinces in China. The results showed that the most money was spent on purchasing agricultural machines in the main grain regions in China where the total power of agricultural machinery was relatively larger. However，the double\|log model showed that elastic coefficients of total agricultural machinery power to agricultural machinery purchase had obvious difference at in main grain regions in China. We analyzed the reasons and then proposed corresponding countermeasures.

Key words: input of purchasing agricultural machines, total power of agricultural machinery, elastic coefficient, panel data model, unit root test, cointegration test