¹⁵N-labelled green manure mixed with nitrogen-free starch was used to feed pigs in the study. The results showed that the amount of ¹⁵N transformed into the bodies of the two slaughtered pigs accounted for 23.51% on average, of the total amount of ¹⁵N deposition in the experimental diet taken by each pig. The ¹⁵N excreted through the feces and urine of the two pigs accounted for 23.85% and 28.76%,respectively, of the total amount of ¹⁵N deposition in the feed (green manure) of pigs. The average recovery of total ¹⁵N for the two pigs was 76.12%.At the same time, the mean digestibilities of carbohydrates for two pigs was 75.63%.The results of rice micro-plot experiment showed that the amount of ¹⁵N transformed from pig feces and urine into whole rice plant accounted for 3.75% and 7.25% of the total amount of ¹⁵N deposition of the feed-green manure respectively, of which 2.51% and 4.82% of the total ¹⁵N were transformed into rice grain, respectively. The pig bodies and rice grain recovered altogether 30.84% of the feed-green manure N, being 15.7% relativly higher than that in the plot of combined application of green manure and urea where rice grain recovered 26.65% of the ¹⁵N-labelled green manure N.