Abstract: To investigate the effects of dietary replacement of fish-soy oil mixtures by palm oil on growth performance, feed utilization, muscular fatty acid composition, morphological index and liver tissue structure of yellow catfish (Pelteobagrus vachelli Richardson), five iso-proteic (400 g/kg), iso-lipidic (100 g/kg) and iso-energetic (15.70 MJ/kg) diets were formulated, in which the control group was supplemented with 1鲶2 fish-soy oil mixtures, and trial groups adopted different palm oil level (10 g/kg, 25 g/kg, 40 g/kg and 55 g/kg) to replace the mixture oil, respectively. For a 8-week trial. The results showed that dietary palm oil replacement had no significant effect on the feed intake, body weight, growth rate, feed efficiency, and protein retention efficiency (P>0.05). All the above parameters were increased with increasing dietary palm oil replacement level up to 25 g/kg, and then decreased. LA and n-3 HUFA concentrations in dorsal muscle significantly decreased with increasing dietary palm oil replacement level (P<0.05), while muscular n-3/n-6 significantly increased with increasing dietary palm oil replacement level (P<0.05). Furthermore, there were no significant difference in condition factor and viscerosomatic index among different groups (P>0.05). However, hepatosomatic index of 55 g/kg palm oil group was significantly higher than that of 25 g/kg palm oil group (P<0.05). The swelling hepatocytes with nuclei displacement and the increasing number of hepatic sinusoid and lipid cells were observed in 55 g/kg palm oil group. In conclusion, palm oil that replace 1鲶2 fish-soy oil mixtures up to 25 g/kg had no significant effect on the growth performance but improved the fatty acid profile of dorsal muscle.