The Induction of regeneration and maturation in the free-living gametophytes of Ecklonia stolonifera Okamura was studied at four temperatures (5, 10, 15, and $20^{circ}C$), four levels of irradiance (5, 10, 20, and 40 ${mu}mol;m^{-2}s^{-1}$) and three photoperiods (14:10, 12:12, and 10:14 h L:D). Female gametophyte fragments were maintained in active regeneration without reaching sexual maturity under $5{sim}10^{circ}C$, 10 ${mu}mol;m^{-2}s^{-1}$, 10:14 h (L:D), whereas the conditions for male gametophytes were slightly different at $20^{circ}C$, 40 ${mu}mol;m^{-2}s^{-1}$, 10:14 h (L:D). The sexual maturation of female and male gametophytes was facilitated at $15^{circ}C$, 20 ${mu}mol;m^{-2}s^{-1}$, 14:10 h (L:D). These results provide basic information for controlling the regeneration and maturation of the free-living gametophytes for artificial seed production of E. stolonifera.