Abstract: The nucleohistones of the liver, spleen, kidney, gill and crythrocyte of silver carp, bighead and their hybrid F1 (bighead carp ♀× silver carp ♂) were analysed electrophoretically. The results of analysis show that the percentage content of histone H1 in total histoine of the liver arid spleen of the hybrids is much higher than that of their parents, while the histone H1 content of the kidney and gill of the hybrids as well as their parents is rather low and among them no obvious difference can be found. Their erythrocytes have histone H5 with same electrophoretie mobility as that in bird's erythrocytes.The possible correlation between the higher histone H1 content in the hybrid F1 and their growth is discussed in this paper, The function of histone H1 in determining special construction of chromatin is also brought to attention.