To study the effects of different dietary starch sources on net absorption of nutrients and energy through portal vein, four crossbreed D×L×Y boars fitted with permanent catheters in the portal vein, mesenteric vein and carotid artery were arranged in a 4×4 Latin square experiment. The results showed that, net absorption of glucose and total amino acids per 100 g feed intake of growing pig in 8 hour postprandial through portal vein in maize group respectively were 27.52 g and 8.89 g, which were significantly higher than those in resistant starch group (P<0.05). The total net absorbed energy through portal vein in resistant starch, maize, brown rice and stick rice group were 676.61, 883.32, 806.16 and 812.44 J,respectively; and compared with that in other group, there was the highest total net absorbed energy through portal vein in maize group; while the total net absorbed energy through portal vein was the lowest in resistant starch diet group, which was significantly lower that than other groups (P<0.05). In the total net absorbed energy through portal vein, absorbed energy in the form of glucose in resistant starch diet group was significantly lower than that in other groups (P<0.05); while absorbed energy in the form of VFA in resistant starch diet group was significantly higher than that in other groups (P<0.05); absorbed energy in the form of lactate was the lowest in all groups and it took up 3.22%～5.41% in the total net absorbed energy through portal vein. The percentage of total net absorbed energy through portal vein in general energy and digestible energy in maize group were 51.59% and 55.55%, which were significantly higher than those in resistant starch group (P<0.05). It implicated that there exist difference in absorption form and energy availability in the digestive tract of pigs among different dietary starch sources; starch sources in the form of glucose supplying more energy had higher energy availabilities, while starch sources in the form of VFA or lactate supplying more energy had lower energy availabilities.