Abstract:In order to meet the demand of high spatial temporal resolution operational for ecast under the situation of abundant NWP products, based on the former recogniz ing study about upper air primary system with contour analysis method, targeting the MICAPS format grid data, using the vector analysis, the algorithms of quant itative parameters for a certain point were setup such as the distance to the af fecting weather system, the intensity, the moving direction and velocity, the te mporal changing rate of the system, the relative position to that system，the lo cation of the jet and the jet intensity also. The quantitative auto analyzing s oftware for upper air major weather systems was developed with visual BASIC language. The experiment on sandstorm i n northern part of China and cold air activity in southern China shows that the algorithm is effective with high accuracy. The algorithm provides a good basis f or developing automatic forecast system and to rise the modernization level for objective forecast.