The data from 1,674 litters of three-breed crosses produced from Yorkshire-Landrace (YL), Duroc-Yorkshire (DY) and Duroc-Landrace (DL) sows mated to purebred Spot and Hampshire boars were analysed by least squares method to estimate the least squares mean of specific 3-breed crosses, to compare among dam crosses, and to compare between sire breeds for total number of pigs per litter at birth, ,number of live pigs per litter at birth, Utter size at weaning and pig weight at weaning at 30 days of age. The results obtained in this study are as follows. 1. Among the six 3-breed crosses compared, S×YL had the largest number of pigs born alive and total number of pigs born per litter. S×DL had the Largest litter size at weaning and H×DL had the largest weaning weight of pig at 30 days of age. 2. Among the three dam crosses compared, Duroc-Landrace sows tended to be superior in the total number of pig born per litter, litter size at weaning, and in weaning weight of pig, although the differences among the dam crosses were statistically insignificant. 3. The 3-breed crosses produced by Spotted boars tended to have larger litter size at birth and apt weaning, but had smaller weaning weight of pig.