Objective To reveal the influence of estrogen replacement threapy on the gap junction connexin 43(Cx43)expression and content of metal elements in ovariectomy and chronic aluminum toxication rat heart. Methods Forty 6-month-old female SD rats were divided randomly into 4 groups: group Sham, group OVX, group OVX+Al and group OVX+Al+ESUB>2/SUB>. After 3 months, The content of metalelements in heart was detected by ICP-AES. The Cx43 expressions were observed and determinated by immunohistochemistry and digital image analysis. Results 1.Cx43 positive granules distributed in cell side surface and cytoplasm as well as intercalated disk in atrial myocytes. They typically confined to the site of intercalated disk in ventricular myocytes in group Sham. In Group OVX, the Cx43 of atrial myocytes were redistributed from cell side surface to the intercalated disk. They were redistributed from the intercalated disk to cell side surface and in cytoplasm in ventricular myocytes. And some Cx43 granules distruibuted irregularly. The Cx43 redistribution of group OVX+Al was more irregular than that of group OVX. In group OVX+Al+E2, the Cx43 distribution of atrial myocytes returned to normal. 2. The amount of Cx43 in all groups was not changed. 3. In sham group，the content of mental elements in heart showed as follows: Mg＞Ca＞Fe＞Zn＞Al＞Si＞Cu＞Mn＞Se and Cd; Compared between group OVX and group sham, the content of Zn decreased (EM>P/EM><0.001); Compared between group OVX+A1+ESUB>2/SUB> and group sham, the content of Al, Cd, Si and Se increased (P<0.05，EM>P/EM><0.01，EM>P/EM><0.01，EM>P/EM><0.001); Compared between group OVX+Al+ESUB>2/SUB> and group OVX+Al, the content of Cd, Mn and Se inc