15-Hydroxyeicosatetraenoic acid (HETE), as a mammalian biologically active metabolite, has anticarcinogenic effect. The conditions of producing 15-HETE from arachidonic acid by using soybean lipoxygenase were optimal at pH 8.5 and $20^{circ}C$ with 9 g/l arachidonic acid, 54.4 U/ml soybean lipoxygenase, and 4% methanol. Under these optimized conditions, the enzyme produced 9.5 g/l 15-HETE after 25 min, with a molar conversion yield of 99% and a productivity of $22.8gl^{-1}h^{-1}$. To the best of our knowledge, this is the first biotechnological production of 15-HETE.