The purpose of this research was to study the chemical compositions of pork for crossbred pig (female, 198 days old $102{sim}118kg$) that were fed with tangerine byproduct from pregnancy through the whole rearing period. The samples for this study consisted of the pork from give the number of control pigs not fed with tangerine byproduct($T_0$), and the pork from give the number of study pigs fed with 8% tangerine byproduct during the whole breeding period, from the early pregnancy through the young, growing and finishing periods ($T_1$). Backfat thickness of the crossbred pigs was significantly decreased by feeding tangerine byproduct (p<0.05). The proximate composition, minerals, total amino acid, saturated fatty acid vs. unsaturated fatty acid and vitamin $B_2$ contents of loins were not significantly different among $T_0;and;T_1$, (p>0.05). Although those differences were not significant statistically, the tangerine byproduct tended to increase the amount of vitamin $B_1$, and decrease the crude fat and cholesterol contents.