Present paper deals about most abundant insect faunal species of PBR, and variation in diversity pattern of insect species in teak –Sal forest ecosystem with seasonal variations. Insect species like Camopnotous, Aciagrion sp, Metochus uniguttattus (Thunberg), Creatonotus gangis (Linn), Ypthima sp, Myrimica sp, Gryllus assimilis (Fabricius)*, Ypthima sp, Clania crameri (Westwood), Scudderia furcata (Braner), and Lasius niger (Linn.) are most abundant and adaptive insect species of Teak- Sal ecotone in PBR, on the basis of richness count. SHE analysis is made to analyze diversity pattern in both ways yearly and seasonally of insect species of PBR