Abstract: The effect of additive of pineapple leaf residue in basal diet on growth of fattening pig was discussed in the article.135 fattened pigs with the same day old and close weight were selected and randomly divided into control group,test group Ⅰ and test group Ⅱ,there were 45 pigs in each group,the supplemented pineapple leaf residue was 0 kg/d,7.28 kg/d and 14.78 kg/d respectively,it lasted for 36 days.The results showed that it had no any bad effect on growth,but there was a remarkable effect on saving concentrate （P〈0.05）;The weight gain of fattening pig in test groups was lower than that of the control,but there was no significant difference between the test group Ⅰ and the control （P 〉0.05）.Based on the above calculation,it had the better effect on adding pineapple leaf residue with 7.28 kg/d.