In order to establish informations important to the measurement of lipoxygenase (LOX) activity, providing conditions most favorable for its action and determining factors that inhibit activity, the influence of extraction buffer, substrate, pH, storage, temperature, NaCl, CaCl₂, other canons and antioxidants on LOX activity, and localization of LOX in cucumber tissues were carried out. The most favored substrate for LOX was linolenic acid followed by linoleic and arachidonic acids. LOX activity in both peel and mesocarp tissue extracts was maximum at pH 5.5 and relatively stable at 40℃ and 50℃ temperature. The condition of 0.2M NaCl with pH 5.0 was observed to provide optimum LOX stability. The enzyme activity was reduced by addition of canons, Mn^(2+), Cu^(2+) or Al^(3+), except Ca^(2+) which stimulated activity of LOX. Butylated hydroxy anisole (BHA) and propyl gallate decreased LOX activity with increasing concentration. Cucumber peel had higher activity than other tissues, locule or mesocarp, of cucumber.