Cadmium compounds are serious pollutants of aquatic environment because of their environmental persistence and ability to be accumulated by aquatic organisms. The present research was designed to study the sub lethal concentration of CdCl2 on some biochemical parameters of Clarias batrachus. The fishes selected for the experiment were 20 in number, arranged in 4 groups, 5 in each group. The average length and weight of Clarias batrachus was 11 inches and 255 gms respectively. One of the 4 groups was kept as control and the rest three  groups were experimental ones exposed to 2.5 mg/litre sub lethal concentration of CdCl2 for the time period of 15, 30 and 45 days respectively. After exposure, it was observed on one hand that the glucose level showed a significant decrease and on the other hand an increase was observed in total protein, cholesterol, albumin and globulin. The result of recent research work clearly indicates that the cadmium disturbs the energy metabolism of Clarias batrachus by and large. This in future will lead to death of fish species and finally affects the whole population of the individual organism.