An. experiment was carried out to determine the genetic variation and covariation in postweaning growth performance (body weights and gain) of New Zealand White (NZW) and Californian (CAL) rabbits. A total number of 2251 rabbits were produced from .775 dams mated to 44 sires. A linear mixed model included the effects of sire and dams within sire (as random effects) and year-season, sex, litter size at birth, parity and all possible interactions (as fixed effects) was used for analysing such data. A set of litter size correction factors for postweaning weights and gains were derived, Weights and gains al different ages in NZW rabbits were slightly higher than in CAL. Coefficients of variation of growth traits at earlier ages were higher than at older ages. Year-season affected (P