ten popcorn populations (pr 038, pr 079, rr 046, sc 016, pr 017, brs angela, sc 002, pr 009, pr 023 and se 013) were evaluated to estimate inbreeding depression and average genetic components. the experiment was a split plot in a randomized complete block design with three replications. the plots were the inbreeding levels (s1 and s0) and the sub-plots were the populations in two locations (maringá and iguatemi-pr) during the 2001/2002 grown season. plant and ear height, grain yield and popping expansion were evaluated. it was observed lower values of inbreeding depression and predominance of additive effects for popping expansion in relation to yield. the sucess of getting high popping expansion inbred lines is higher with brs angela and sc 002 populations.