Chloroplast fructose-1,6-bisphosphatase from pea seedlings was purified to homogeniety. Polyclonal antibody was raised from the purified enzyme and used for cDNA cloning and immunoblot analysis. The amino acid sequence of the coding region of cloned cDNA was 83-85% homologous with that of chloroplast enzyme from wheat and spinach, whereas it was only 43% homologous with that of spinach cytosolic enzyme. The enzyme activity of chloroplast fructose-1,6-bisphosphatase was markedly increased by light: illumination. Immunoblot and northern blot analysis indicate that the expression of the enzyme was stimulated by red light while repressed by far red light, suggesting that the enzyme expression is regulated by phytochrome. The enzyme was maximally expressed in pea leaves but not expressed in stems and roots.