Abstract: Objective To analyze the expression of protein kinase C(PKCs) related signal pathway factors in human growth hormone(GH) type pituitary adenoma cells and its mechanism of regulating cell proliferation. Methods Eight patients with GH type pituitary adenoma were treated with resection of tumor tissue for primary culture. The expression of PKCδ, CREB and ERK1/2 in the cells was detected by immunohistochemistry. The primary cultured cells were divided into control group(blank), agonist group(PMA), inhibitor group(rottlerin), combination group(PMA+Rottlerin), 8 cells in each group. The GH secretion level of each group was detected by ELISA, the cell activity was detected by CCK-8, the factors and phosphorylation level were detected by western blot. The data was analyzed by SPSS 21.0 software package. Results PKCδ, CREB and ERK1/2 were more common in the cytoplasm of GH pituitary adenoma. Compared with the control group, GH secretion and activity increased in the agonist group, but significantly decreased in the inhibitor group(all P<0.01). Compared with the control group, the levels of p-PKCδ, p-CREB and p-ERK1/2 in the agonist group increased, while those in the inhibitor group decreased(all P<0.01). The levels of p-CREB and p-ERK1/2 in the combined group were lower than those in the agonist group and higher than those in the inhibitor group(all P<0.01). Conclusion PKCδ, CREB and ERK1/2 are highly expressed in GH pituitary adenoma cells. Activation of PKCδ can increase the level of p-CREB and GH secretion, and increase the level of p-ERK1/2 to promote cell proliferation.