Chloroplast fructose-1,6-bisphosphatase was purified 1,300 fold from pea leaves. The purified enzyme appeared homogeneous and the approximate molecular weight of the monomer was 40,000, as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The enzyme was inactive at pH 7.5, while it was activated by dithiothreitol or alkaline pH, indicating that the purified fructose-1,6-bisphosphatase was originated from chloroplast. The enzyme saturation curves with fructose-1,6-bisphosphate and Mg^(++) show sigmoidal shapes with almost same Hill coefficients (2.6 and 3.1, respectively), suggesting that the enzyme is composed of multimer. The substrate concentration required for half-maximal activity was 40 μM which is a comparable value (80μM) for spinach chloroplast fructose bisphosphatase (Zimmermann et al., 1976).