The effect of LHRH-A (des-Gly¹⁰, D-Ala⁶ LHRH-ethylamide) incombination with dopamine antagonist PIM or catecholamine depletor RES on gonado-trophin secretion and ovulation of the cultured fishes were investigated. Injection of themixture of LIIRH-A and PIM or LHRH-A and RES is highly effective in stimulatinggonadotrophin secretion and inducing ovulation or spawning of freshwater culturedfishes. The rates of spawning in our experiment were: black carp (Mylopharyngodonpiceus) 80%; silver carp (Hypophthalmichthys molitrix) 84%; bighead carp (Aristi-chthys nobilis) and grass carp (Ctenopharyngodon idellus) 88%; bream (Parabramispekinensis) 94%; and mud carp (Cirrhinus molitorella) 96%. The advantages of theseovulatory agents are high rate of ovulation, complete replacement of carp pituitary;beneficial to the protection of brooders as well as labour saving and low cost.