Abstract: The overconfidence psychology is one of the unreasonable psychologies existing in the financial market,which has important influence on the prices of the financial products.Combining with the characteristics of the futures market,this paper establishes a mathematical model of the influence of the overconfidence on the futures market price.Through the model,we deduce some of the conclusions that overconfidence will result in more trade volume of the speculators and arbitrageurs who contain overconfidence psychology;the extent of overconfidence between speculators and arbitrageurs will influence the trend of the mean of equilibrium futures price;and overconfidence psychology can weaken the fluctuation of the futures price caused by noise traders.At last,the method of simulation is employed to verify the conclusions above.

Key words: overconfidence, speculate, arbitrage, futures price