The bulk of silk produced in India is from Multivoltines which are of inferior quality. Therefore, it is highly pertinent to have more productive bivoltine silkworm breeds capable of producing quality silk. However, the hot climatic conditions of India is not conducive to rear productive bivoltines. It is a well established fact that the bivoltines are highly vulnerable to high temperature coupled with high and low humidity especially in the late instars. The hot climatic conditions of tropics prevailing particularly in summer are contributing to the poor performance of the bivoltine breeds and the most important aspect is that many quantitative characters such as viability and cocoon traits decline sharply when temperature is high. Therefore, it is highly pertinent to identify more number of bivotine breeds which can withstand adverse climatic conditions. Accordingly, the present study was carried out to select suitable bivoltine breeds to be used as breeding resource materials for the development of bivoltine silkworm hybrids suitable to West Bengal conditions of India.