To find the cause of PSE porcine muscle occurring in pig chemical composition of meat, intra-muscullar fat and the phospholipid content of pig were analyzed. The results are summarized as follows. 1. Backfat thickness and tat content showed a significant difference (P$lt;0.01) between the female pig and the male pig. The females were more fat content and higher percentage of PSE porcine muscle incidence than the male pigs. 2. The PSE porcine muscle occurred frequently in the loin portion in pig and female pigs showed severely higher incidence than the male pigs. 3. The body composition varied with increasing body weight in pig. The most obvious difference between female and male was the fat content and backfat thickness 4. The experiment has not found a significant difference between male and female in the fat content, but the females had a greater content of fat than male. Body weight a significant difference (P $lt; 0.01) between male and female.