31 Women with hyperprolactinemia (HP) and 30 women with normal lu teinizing phase of cycles were investigated in this study. The patients were divided into pituitary adenoma group(Ⅰ) and functional HP group(Ⅱ) by CT and MRI examinations. Each group above was subdivided into hypoestrogenic(hypoestrogenic Ⅰ, hypoestrogenic Ⅱ) and euroestrogenic (euroestrogenic Ⅰ, euroestrogenic Ⅱ) groups by means of estrogen levels and cervical mucus. Basic hormone levels of all groups were measured by radioimmunoassy(RIA). The results showed that the prolactin levels were higher and LH, FSH, E_2 T and P levels lower in women with HP than in control women. The prolactin levels of Ⅰ exceeded these of Ⅱ markedly. LH, FSH, E_2, T and P were similar in both Ⅰ and Ⅱ. LH and FSH were similar in both hypoestrogenic and euroestrogenic groups except E_2. In summary, this study indicates that (1) The patients may present hypogonadotropic and hypogonadal functions; (2) Gonadotropic and gonadal functions of Ⅰ are similar to those of Ⅱ; (3) There is probably size heterogeneity of prolactin in pituitary adenoma and functional HP.