Rajasthan is very rich in terms of biological diversity due to its unique bio geographic location, diversified climatic conditions and enormous eco-diversity and geo-diversity. Class Insecta play important role in diversity.it is largest class in Kingdom Animalia. In class Insecta most diversified order is Coleoptera. It is estimated that out of about 8, 00,000 described species of insect world over, Coleoptera alone shares about 3, 50,000 that belongs to 4 sub orders and 177 families. At Rajasthan 16 family and 140 species of Coleoptera is reported. Most of diversity are reported by 4 families Scarabaeidae, Curculionidae, Dytiscidae, Hydrophilidae.