Objective To investigate the effects of inflammatory factors TNF-α, IL-1β, IL-6 on expression of mechano growth factor (MGF). Methods In the experimental group, TNF-α and IL-6 at concentration of 25, 50, 100 ng/mL, or IL-1β at concentration of 2.5, 5.0, 10 ng/mL were applied to fibroblast-like synoviocytes (FLSs) for 12 hours. The inhibitor groups were pretreated with PKA pathway inhibitor KT5720 at concentration of 1.0 mmol for 1 hour. The control group remained under the same culture condition as the experimental group, but without any growth factor. Real-time PCR was used to measure the gene expression of MGF. Results Treated with TNF-α at concentration of 25 ng/mL and IL-1β at concentration of 10 ng/mL, the MGF expression in FLSs was significantly increased (P＜0.05). IL-6 had no effect on MGF expression. A specific inhibitor of cAMP-dependent protein kinase, at concentration of 1.0 mmol significantly decreased the activation of MGF synthesis by TNF-α and IL-1β in FLSs (P＜0.05). Conclusions TNF-α at concentration of 25 ng/mL and IL-1β at concentration of 10 ng/mL significantly induce the MGF expression in FLSs, which activate MGF synthesis via the PKA pathway. This study is of significance in improving the application of MGF used in tissue repair area to make up the insufficient stress stimulation.