An analysis on the deterministic contract decomposition algorithm of East China electricity market is presented. Two indices of the average contract quantity proportion， the correlation of contract quantity proportion and price are adopted to evaluate the equity of the algorithm. Expectation， standard deviation and half standard deviation are used to evaluate the income and risk of generators. An empirical analysis is undertaken based on the historical data of East China electricity market. By use of the algorithm， the results indicate that the buyer and generators are treated equally and the generator risk is reduced effectively.