Abstract: This study comparatively analyzed the change regulation of serum growth hormone of transgenic fish and control under starvation and feeding condition by using the Enzyme-linked immunosorbent assays,ELISA technology,and discussed its possible mechanism.The result showed that there was no obviously change in serum growth hormone level of both transgenic fish and the control in feeding experiment,but serum growth hormone level of the former was extremely higher than the latter,which were(142.0±4.9)ng/mL and(1.6±0.2) ng/mL respectively,body weight growth rate of the former was also higher than the latter.In starvation experiment,the concentration of serum growth hormone in transgenic fish descended from(142.0±4.9) ng/mL to(46.0±3.2) ng/mL rapidly,and then kept at this lower level,while the concentration of serum growth hormone in the control rose up from(1.6±0.2) ng/mL to(10.9±1.4) ng/mL continuously,there was no significant difference in body weight minus growth rate between transgenic fish and the control.The study result revealed that the regulatory mechanism of serum growth hormone of transgenic common carp was different with that of the control,because its expression level was not impacted by pituitary feedback inhibition mechanism but related to the control mode of β-actin gene promoter in the transgene.