Androgen plays an important role in the regulation of gonadotropin production in vertebrates . We have investigated the transcriptional pattern of androgen receptor (AR) in a variety of tissues in maturing male and female goldfish by RT-PCR. Specific primer for AR was designed based on goldfish AR gene from the GenBank (accession number AY090897). AR was shown 10 be maturity- and tissue-dependent gene expression pattern in goldfish. In immature male goldfish, significantly higher transcript level of AR was observed in the pituitary und testis , compared [0 brain and liver. Mature male goldfish showed a similar expression pattern to immature male goldfish. Interestingly. when compare to male goldfish, female goldfish showed AR mRNA expression that was found 10 be weak in pituitary, and very low expression in brain. They could not be found 10 have expression in any other tissues. Taken together. the- transcriptional analysis of AR depending on the tissue, sex. and maturity of a goldfish provides the opportunity for the study of goldfish reproductive physiology ,The results provided for the first time a comparison of the tissue distribution of AR mRNA in sexually maturating male and female goldfish.