Abstract: Based on the annual data from 1980 to 2009, which passed the Johansen cointegrated verification and Granger causality verification, this article established the direct effects model and state space model to analyze the relationship between electricity, coal andoil's prices and energy efficiency. The results show that energy efficiency and price of the three types of energy has a long-run equilibrium relationship, and their rise can improve energy efficiency; and their effect on energy efficiency gradually weaken as the order:electricity price, oil price and coal price, but this improving degree is very small. Currently, it is hard to improve energy efficiency only by means of energy price. Besides, the substitution between energy can slightly and steadily improve energy efficiency. The promoting effect of three types of energy price on energy efficiency is increase in fluctuation. Based on this, this article analyzes the problem and offers advices for how to make full use of energy prices to improve energy efficiency.