Rearing experiments were conducted using several regimes combined with different photoperiods and water temperatures to investigate the role of temperature and photoperiod as environmental cues regulating reproduction in red marbled rockfish, Sebastiscus tertius. The initial gonadosomatic index (GSI) was 1.62±0.32% and that in the 15˚C control was 7.01±0.46% at the end of the experiment. The highest GSI was 9.10±0.35% in the 12L:12D photoperiod-treated fish. The highest GSI at 19˚C was 15.03±0.86% in the 12L:12D photoperiod treatment. The initial hepatosomatic index (HSI) was 3.09±0.72% and that in the 15˚C control was 3.88±0.45%. The highest HSI was 4.00±0.56% in the 15L:9D treated fish. The highest HSI at 19˚C was 4.05±0.63% in the 12L:12D treated fish.