Abstract:A phosphatase was partially purified from rice leaves by the steps of acidification (to pH 4. 5), ammonium sulfate precipitation, Sephadex G-50 chromatography and DEAESepharose chromatography. ItS Km (PEP) was 0. 1 mmol/L with an optimum pH 5. 3, andwas heat-stable and lossed few activity in the range of pH 4. 0-7. 2. Its activity was potently inhibited by Pi. The enzyme was not specific for its substrate, and could hydrolyzea wide variety of phosphate esters. The results indicated that the enzyme was a non-specificacid phosphatase. Various phosphate ester metabolites exhibited additive inhibition effect on it and was competitive with respect to PEP. The enzyme activity was also inhibited byCu2+, Zn2+, and Fe2+, and unaffected by Mg2+, Mn2+, Ca2+, Co2+, and EDTA.