According to "the criterion of surface meteorological observation"，visibility and wind speed are important targets to classify dust一stormy weather.  Using the data of visibility and wind speed observed in meteorological stations，we try to construct duststormy weather index to determine the intensity of dust一stormy weather phenomenon，moreover we can measure the strong or weak state of dust一stormy weather happened anywhere.  We have obtained thefollowing conclusions ahe dust一sand index can corre}ond with the intensity of dust一stormy weather ;our analysis to state of dust一stormy weather in different area is in corre}ondence with real weather facts.  The correlative analysis between sand一dust index and urban airpollution index indicated their affinity. It ispossible to build urban air pollution statistical forecasting model with the sand一dust index.