Abstract: Normal synovium is mainly composed of fibroblasts and macrophages. In the pathological process of rheumatoid arthritis (RA), the “tumor like” transformation of fibroblasts is considered to be related to inducers secreted by M1 macrophages. They are manifested as excessive proliferation, decreased apoptosis and abnormal secretion of pro-inflammatory factors, which in turn stimulate the macrophages for M1 polarization. However, the effect of M1 macrophages on fibroblasts and vascular endothelial cells has not been reported. In this study, we aim to reveal the interactions between different types of cells in the RA synovium. mRNA expression of IL-8 and eNOS in M0 and M1 macrophages derived from human myeloid leukemia monocytes (THP-1) were detected by real-time fluorescence quantitative method. Moreover, the concentration of inflammatory factors in the supernatant of THP-1 derived M1 macrophages was determined by enzymelinked immunosorbent assay. In addition, the proliferation of fibroblasts and vascular endothelial cells was investigated by CCK8. The results showed that interlekin-1β and interlekin-8 proteins were mainly secreted by THP-1 derived M1 macrophages. We found that the rheumatoid arthritis synovial fibroblasts (MH7A) treated with mixture of M1 macrophage supernatant and serum-containing roswell park memorial institute (RPMI) with the ratio of 7∶3 for 48 h, and the cells proliferation was improved. Meanwhile, the proliferation of human umbilical vein cells was remarkable enhanced after treated with the mixture ratio at 6∶4 or 7∶3 for 72 h. Based on this study, we will further establish the in vitro RA pannus model in future, which will facilitate the generation of high-throughput screening techniques for anti-RA drugs development.