Objectives: To study the expression and significance of cell cycle proteins CyclinD2, mPGES-1, Bcl2 in diffuse large B-cell lymphoma. Methods: Choose lymphoma and sexually hyperplastic lymphoid tissues as control. Immunohistochemical methods were used to detect the expression of CyclinD2, mPGES-1, and Bcl2, and to compare the positive expression rates of CyclinD2, MPGES-1 and Bcl2 in diffuse large B-cell lymphoma and reactive proliferative lymphoid tissues to compare their diffusion formation. B-cell lymphoma was analyzed for its clinicopathological features. Results: The positive expression rate of CyclinD2, mPGES-1 and Bcl2 in diffuse large B-cell lymphoma is higher than that in reactive proliferative lymphoid tissue, and the difference between the two is statistically significant. There was no statistical difference in CyclinD2, mPGES-1 and Bcl2 in diffuse large B-cell lymphoma between patients according to the age, sex, location, tissue type and degree of differentiation. Conclusion: CyclinD2, mPGES-1 and Bcl2 are highly expressed in patients with diffuse large B-cell lymphoma, and can be used as reference indicators for evaluating the malignant degree and efficacy of dysplasia.