We used filter paper contact test method for obtaining LC50 for python and dieldrin. This Organophosphate is very poisonous, which affects the body and Growth of Earthworm. We had seen in the test solution of 0.8mg/cm2, 0.9m g/cm2 and 1mg/cm2of 1% dieldrin, all earthworms died and melt. Similarly, cythion 0.3 and 0.27 showed the same result. This concentration was shown super toxic to earthworms. In the test solutions of 0.1mg/cm2 and 0.2mg, the earthworms were very active and not stationary. In test solutions of 0.3mg/cm2 and 0.4mg/cm2 the earthworm was slightly less active, and in 0.5mg/cm2, the concentration of test solution earthworm was live and less active in this experiment. Similarly the 0.03m g/cm2, 0.06 mg/cm2 and 0.09 mg/cm2 concentration showed same effect for cythion. We used three replica test set for the better resulting and calculated mortality. At the end of the experiment, we observed that 0.5 mg/cm2concentration of dieldrin and 0.15m g/cm2 for cythion was shown LC50 value of mortality. In some set like 1 mg/cm2, 0.9 mg/cm2 was very highly affected on earthworm they had been broken, melt and the body had destroyed. It was shown directly effect on the earthworm’s body and growth.