The protein content was highest in the ovaries ofPuntius chilinoides during the maturing stage and in the testes during the mature stage. The activity of the acid phosphatase and the number of isozymes decreased in the testes during maturation, whereas in the ovaries the activity increased during the maturation and spent stages. The alkaline phosphatase activity in the testes increased during maturation phase, while in the ovaries the highest activity of the enzyme was recorded at the maturing stage and the lowest during the mature stage. Cholesterol level in the ovaries was highest during the maturing stage, while in the testes it was noticed during the immature stage. The sugar contents in the gonads were highest at the mature stage. The results are discussed in relation to the reproductive cycle inP. Chilinoides.