Abstract:Enzymes are special proteins that catalyze and regulate a series of life processes in plants. Studies on in situ histochemical, cytochemical, immunological and microscopical localizations of metabolism enzymes in intact plant tissues and cells are important approaches in understanding the distributions, activity dynamics and quantifications, and functions of enzymes within tissues, cells and organelles. The basic concepts, principles and research progresses of histochemical and cytochemical localizations of enzymes were reviewed. According to the international enzymology classification and taxis, the reaction media and staining method of histochemical localizations on 25 plant enzymes and references of cytochemical localizations on 46 plant enzymes were introduced, respectively.