For the determination of radiostrontium, $^{89}Sr;and;^{90}Sr$ in environmental soil sample, a solvent extraction method for the separation of Ca and Sr from matrix using crown ether was investigated. In comparison with the existing fuming nitric acid method, the extraction method showed high chemical yield of strontium and provided simple and rapid analytical steps. The new analytical method applied to the determination of radiostrontium in some soil sample around a nuclear power station to show that the analytical procedure is readily applicable to the practical radioactivity monitoring.