The present study deals with demonstrate the reproductive cycle of the broomtail wrasse, Cheilinus lunulatus which monthly collected from coral reef in Abu Galawa lagoon, Hurghada, Red Sea, during the period from December 2011 to
November 2012. Results showed that, the averages of male and female gonadosomatic indices (GSI) were gradually increased during spring and summer months. Irregular trend was recorded to the female hepatosomatic index during all months of the year. It may be due to partially spawning in this fish. Shape, weight, size, colour, texture and structure of gonads were changed with the change of maturity stages. The testicular activity can be classified into five stages: immature stage, stimulating spermatogenesis, rapid spermatogenesis, mature (ripe) testis and Spent testis. Seven stages were recognized during the ovarian activity (previtellogenesis, earlyvitellogenesis,
mid-vitellogensis, late-vitellogenesis, pre-spawning, ripe and spent stages). The tsticular and ovarian developments were initiated when the day length (photoperiod) and water temperature had begun to increase during March to April. During May to August, however, the gradual increase of both photoperiod and water temperature reached its maximum values, gonads had ensured completion of testicular and ovarian development. It was concluded that Cheilinus lunulatus in Abu-Galawa lagoon of Hurghada, partially spawned during a long spawning season, which extended from May to October. It synchronizes between both males and females with coordination to increasing of both photoperiod and water temperature.