Abstract: In order to investigate the effects of slaughter weight on meat performance, muscle quality and economic benefits of large Diqing Tibet pigs, thirty-six castrated and weaned large Diqing Tibet pigs with the same parity and similar birth date were randomly divided into 3 groups（group 1, group 2 and group 3） for fattening test, and were slaughtered when the average weight reached 40 kg, 80 kg and 120 kg, respectively. The fattening performance（average daily gain, feed/gain）, slaughter performance（slaughtering weight, carcass weright, carcass straight length, carcass oblique length, average backfat thickness, 6-7 intercostal fat thickness, skin thickness, eye muscle area, ratio of abdominal fat, dressing percentage, skin ratio, bone ratio, lean meat ratio, fat ratio）, muscle quality（pH₁ value, meat color, marbling, water loss ratio, cooked meat ratio, drip loss） were measured. The number of fattening pigs and the amount of pork（carcass） per pig per year were calculated, and the economic benefits of different slaughter weights were analyzed. The results showed that the average daily gain of full trial period the group 3 and group 2 was significantily higher than that in group 1（P＜0.01）. The feed/gain of full trial period increased with the increase of body weight. The slaughtering weight, carcass weright, carcass straight length, carcass oblique length, average backfat thickness, 6-7 intercostal fat thickness, ratio of abdominal fat in the group 3 were extremely significantly higher than those in group 2 and group 1（P＜0.01）, and those in group 2 were higher than those in group 1（P＜0.01）. The skin thickness in group 3 was extremely significantly higher than that in group 1（P＜0.01） and group 2（P＜0.05）. The loin-eye area in group 3 was extremely higher than that in group 2（P＜0.05） and group 1（P＜0.01）, and that in group 2 was higher than that in group 1（P＜0.05）. The skin ratio and bone ratio in group 1 were extremely significantly higher than those in group 3（P＜0.01） and group 2（P＜0.05）. The lean meat rate in group 1 was extremely significantly higher than that in group 2 and group 3（P＜0.01）, and the fat rate in group 3 and group 2 was extremely significantly higher than that in group 1（P＜0.01）.The water loss rate and drip loss in group 1 was significantly higher than that in group 3（P＜0.05）, but there was no significant difference between group 1 and group 2（P＞0.05）. The cooked meat rate in group 1 was extremely significantly higher than that in group 3（P＜0.01）, and that in group 2 was significantly higher than that in group 3（P＜0.05）. The number of fattening pigs per pig per year was 12.11, 11.98, 12.05 in experimental pig farm, respectively. The amount of pork（carcass） per pig per year in group 1, group 2 and group 3 was 317.59, 689.06, 1001.77 kg, respectively, and the average gross profit was 210.67 yuan, 310.27 yuan and 294.11 yuan, respectively, among which the average gross profit in group 2 was the highest during the whole experiment period. The results indicated that the meat quality and economic benefits of large Diqing Tibet pigs were better when the slaughter weight was about 80 kg.