The present study focuses on early life cycle of Siamese Fighting Fish, Betta Spenden spp.and it’s behavior during mating.This study was conducted in order to determine the stage of life cycle of Betta Splenden spp.. Information that obtained from this study can be applied extensive, semi extensive and intensive farmers to prepare the best condition as one action to reduce the mortality rate at larvae stage. The study was conducted in the laboratory for a week. The ﬁndings from this study indicate that Betta Splendens spp. shows its aggressive behavior towards other male Betta and female Betta during mating process. The study also prove that leave of Terminalia catappa Linn helps in maintain the pH level of water in the tank and induce the sexual of Bettas during mating. In one complete life cycle of Betta Splendens spp. there are 8 stages. Which are started with, bubble nests, eggs, fry, free swimming, labyrinyh, juvenile, sexual matyrity and ended with adult. To complete one life cycle, normally take 3-6 months depends on the temperature, pH and salinity of the Water. Success in this study will be one of the measures to boost economic sectors in Malaysia ornamental ﬁsh.