In this paper,by reviewing the sales statistical data in the past and analyzing the commodities market potential,the author aims to fit out an appropriate demand function and set up models of commodities optimal markdown amplitude.

In this article we applied demand function theory to analyze demand of the whole nation people and the people of Chinese Towns in west , and establish single demand Function Model.

According to the change of domestic water the demand and industrial water demand a water demand function is deduced.

But we may deduce and define the countries’ inter/outer market occupying index and analyze their influences on a country’s equivalent outcome and expenditure multiplier by reconstructing the traditional aggregate demand function.

Based on the rationed equilibrium of IS-LM model under interest regulating, the paper proposes China s aggregate demand function in Monetarian style, implying the only monetary policy matters and fiscal policy is important.

Based on the rationed equilibrium of IS-LM model under interest regulating, the paper proposes China s aggregate demand function in Monetaristic style, implying that only monetary policy matters and fiscal policy is impotent.

Using the cross-section data from 227 domestic passenger route markets in China,this paper applies a regression analysis on China civil aviation\'s domestic passenger route markets,estimates a reverse demand function of these markets.