Adding ratio of consumption into the method of Frisch estimation of elasticity of demand and price, and by mathematical derivation, we derive a group of equation of the estimation of elasticity of demand and price. The research shows: As far as the self elasticity of demand and price is concerned, the self price of commodity has the most impact on its own demand, and the other price of commodity has less impact. As the increase of the rank of income, the sensitive of the demand of commodity to its price change is more and more obvious. As far as the cross elasticity of demand and price is concerned, the price of food has the most impact on it’s the other commodity. As the increase of the rank of income, the level of impact of food price to the other commodity has less and less implication.