〔Abstract〕 Objective To explore the differences in the effects of psoriatic serum and a mixture of five proinflammatory cytokines on keratinocyte inflammation and proliferation. Methods The human immortalized keratinocyte cell line(HaCaT cells) was used to cultivate with serum of healthy human serum, psoriasis patients and M5 factors, and the cell proliferation was monitored by CCK-8. RT-qPCR was used to detect the mRNA expression levels of inflammatory factors interleukin 1β/8/21/23(IL-1β/8/21/23), proliferation markers keratin 6/16(K6/K16) and nucleus related antigen 67(Ki67) in HaCaT cells in each group. Results Healthy human serum, psoriasis serum and M5 factors could effectively promote the growth of HaCaT cells, and psoriasis serum and M5 factors could promote cell growth more than healthy human serum. Similar to M5 factors, serum from patients with psoriasis significantly promoted the mRNA levels of inflammatory factors IL-1β, IL-8, IL-23 and proliferation markers K6 and Ki67 in cells. Different from M5 factors, the serum of psoriasis patients had enhanced the mRNA level of inflammatory factor IL-21, but weakened the promotion of proliferation marker K16. Conclusion The serum microenvironment of patients with psoriasis can promote the proliferation and inflammatory response of keratinocytes higher than that of healthy people, and is similar to M5 factors, which can be used to build a keratinocyte model of psoriasis.