Abstract: Grass carp, Ctenopharyngodon idellus ( C. et V. ) , w eighing about 15g, w ere fed on a cont rol diet and on three treatment diets containing 4, 6 and 8% soybean phospholipids respectively. After a 52- day feeding t rial, the fatty acid composit ion of hepatopancreas lipids w as determined by gas..liquid chromatography. Compared w ith the cont rol g roup f ish, hepatopancreas lipids of the three treatment group fish fed on diets supplemented with soybean phospholipids showed a hig her level of 18..2n- 6 and a low er rat io of 20..4n- 6/ 18..2n- 6. On the contrary, the content of 18..3n- 3 decreased by 30% ~ 69% and that of total n- 3 long..chain ( C ..20) highly unsaturated fatty acids ( n- 3 HUFA: 20..5n- 3, 22..5n- 3 and 22..6n- 3) increased, forming a markedly high rat io of n- 3 HU FA/ 18..3n- 3. The results obtained in this experiment indicated that the supplement of soybean phospholipids to diet s affected the fat ty acid composit ion of hepatopancreas lipids in g rass carp, and improved especially the level of total n- 3 highly unsaturated fatty acids.