In the present work an attempt has been made to study the effect of weedicides – Bromacil and Biofenox on changes in biochemical composition in whole body in a fresh water air breathing teleostean fish, Channa gachua (Ham.). Exposure of sublethal concentrations of both the weedicides brought considerable decrease in lipid, carbohydrate and ash content in stomach, intestine, liver, ovary and testis. The protein content did not vary to a significant level after such treatment. However, the water content in various organs increased to a considerable level. The reason for such changes has been discussed in this paper.