Abstract:A comparative study of six methods for deteemining available phosphorus on calcareous soils in Shensi was made,results obtained from which were checked against pot cultures and azotobacter plaque technique.The correlation coefficients of the six methods in respect to biological tests are given in following order:Olsen's 0.5M NaHCO3 method, Machigen's 1% (NH4)2C2O4 method,Radet's 3.5% sodium citrate method,Egner-Rim's lactate method,Burriel-Hernando's method and Joret-Herbert's 0.2N (NH4)2C2O4 method. Olsen's NaHCO3 method seems to be a better one over the other methods to dcterminc available phosphorus in calcareous soils.