Adminstration of massion doses of estradiol benzoate into malefish caused an increase of vitellogenin and caleium levels in serum and prolifica-tion of rough endoplasmic reticulum and mitochondria in liver cells. Meanwhile,a lot of calcium presented in liver cell's cytoplasm. There was also calcium inthe liver cell of naturally matural female fish. But the liver cells of the male fishwithout injection of estrodiol benzoate had few calcium. This suggested that cal-cium had some effects on the synthesis of vitellogenin, The injection intraperi-toneally with calcium chloride caused the expansion of egg's diamater and increa- se of protein content in oocytes. When the female fish was injected with calciumchloride,the diameter of oocytes was 1.08±0.14mm(n=60)and the protein content was29.14%. As to the control,thes relevant data were 1.04±0.14mm (n=60)and 14.60%.The capillary onfollicular membrance with calcium chloride was dencer than con-trol. This indicated that calcium could enhance the growth of oocytes and theabsorption of protein, especially vitellogenin.