The endocrine axis of growth hormone-insulin-like growth factorⅠ plays a critical role in adjusting fish growth. Meanwhile，nutritional status exerts a complicated effect on the axis. In this study，real-time fluorogentic quantitative RT-PCR （rfqRT-PCR） was used and the effects of fasting on growth and hepatic insulin-like growth factor （IGF-Ⅰ） mRNA expression abundance in 1-year aged largemouth bass，body weight （100±1）g，were evaluated. During a 6 weeks’ trial，control fish （Control group） were fed to apparent satiation twice daily，while test fish （Fasted group） were fasted over the first 3 weeks and re-fed over the later 3 weeks. At the end of the trial，the body weight and body length of the control fish gradually increased by 10.99% and 3.07%，respectively. Those of the fish fasted for the first 3 weeks reduced by 5.08% and 1.79%，respectively. During fasting，IGF-ⅠmRNA expression abundance in liver came to downtrend ending in 29.93%，significantly lower compared to that of the control fish（P <  0.01）. After 2 weeks of re-feeding，the hepatic IGF-ⅠmRNA level was still significantly lower（P <  0.05）and the body weight and body length restored to 96.54% and 99.03% of the initial values，respectively. After 3 weeks of re-feeding，the expression of hepatic IGF-1 mRNA did not show significant difference compared to that of the control fish（P  >  0.05）. But the fish restored only to the initial levels in body weight and body length. These results showed that fasting caused body weight and length losing with reduction of hepatic IGF-ⅠmRNA expression in largemouth bass and that re-feeding resulted in restoration in body growth and expression of hepatic IGF-ⅠmRNA. It was conducted that there was a positive correlation between nutritional status， growth and hepatic IGF-ⅠmRNA level. In most juvenile vertebrates，plasma GH is increased rather than decreased under conditions of nutritional restriction. Current evidence suggests that the biosynthesis of IGF-Ⅰis a key control point for nutritional regulation of growth. Plasma IGF-Ⅰpeptide levels and hepatic IGF-ⅠmRNA abundance are correlated with growth velocity and are consistently decreased when growth is arrested by nutritional deprivation. As for fish，many important questions need to be answered to fully understand the nutritional roles of IGF-Ⅰand the underlying molecular basis. The effect of nutritional status on the autocrine or paracrine of IGF-Ⅰin fish remains unclear. In addition，it is essential to investigate whether individual nutrients，such as amino acids，energy，minerals and vitamins，regulate IGF-Ⅰgene expression and biological activity in fish as in mammals. These pending findings will contribute to completely understanding information on fish IGF-Ⅰphysiology.