An attempt to explore an application of spherical function coefficient data of 500hPa monthly mean height field in flood/drought prediction,it shows the sectorized flood/drought index I in spring and summer of Shaanxi,with being defined on the basis of sectorized precipitation index(I_R)and historical record,the inter-annual anomaly of spherical function coefficients of low dimension and low order are obtained,they can be used as parameters in actual prediction. Based on the analysis of synchronous and time-lagged correlation of the flood/drought index and circulation anomaly,it is found that the relation between the Northern Hemispheric circulation anomaly and flood/drought of Shaanxi is statistically significant while the relation between the Southern Hemispheric circulation anomaly and flood/drought of Shaanxi is not significant.