The studies on biological attributes of laboratory and field populations of Chilo partellus (Swinhoe) on maize were conducted during kharif season, 2012 in the Punjab. The variation, if any, in important biological characters of 3 different populations i.e. P1 (laboratory population reared for 8 generations under laboratory conditions), P2 (field collected population reared for 3 generations under laboratory conditions) and P3 (field collected population reared only for 1 generation under laboratory conditions); and their response to different maize cultivars (i.e. PMH 1, JH 3459 and CML 67) was studied under laboratory; and field conditions, respectively. Their relative susceptibility to insecticides (i.e. Decis 2.8 EC and Dipel 8L) was also studied under laboratory conditions. The mean incubation, larval and pupal periods (male and female) were highest in P1, intermediate in P2 and lowest in P3 while, the mean per cent hatchability of eggs, per cent pupation, pupal weight (maleand female), adult longevity (male and female) and fecundity was highest in P3, intermediate in P2 and lowest in P1.