It is true that the proper environmental risk assessments for many GM insects almost have not been executed in Korean research situation. Therefore, we tested the environmental risk assessment of GM silkworms if there is any difference between GM and non-GM silkworms by three. First, we measured their mobility in the breeding environment conditions with food and without food. Secondly, we measured their viability at the Korean artificial extreme environmental conditions (temperature, humidity, food) after escaping from their breeding environments. We observed the egg productivity and the hatchability between non-GM silkworm and transgenic silkworms with four different pair experiments. The mobility of non-GM silkworms and GM silkworms statistically did not differ and the egg production and hatchability was not also different. The hatchability by couple of GM female silkworm and non-GM male silkworm was lower than by non-GM male and female couple. We observed their viability (High Temp., wet and with food: p=0.0434; High Temp., wet and without food p=0.0430; High Temp., dry and with food: p=0.0005; High Temp., dry, without food: p=0.0479) between the GM silkworm and non-GM silkworm, and there was statistically different. Relatively, the viability of GM silkworm was lower than non-GM silkworms. We could not exactly test for viability of silkworm in low temperature conditions because of their hibernating. Although there was any difference in viability and hatchability between GM silkworm and non-GM silkworm, the all ability of GM silkworm was lower than non-GM silkworm. Conclusively, risk of GM silkworm was lower than non-GM silkworm.