Abstract: Objective To improve the understanding of lymphoma and assess the adenosine deaminase（ADA） levels in nontuberculous pleural effusions of different actiologies. Methods A case of lymphoma with high pleural effusion ADA levels as initial symptom was retrospectively analysed，including clinical manifestation and examination. Results The male patient was 71 years old，had dyspnea for one month，with large pleural effusion in left as initial symptom.ADA levels of the pleural effusion were 620.7U/L.Finally，pleural biopsy was performed and pathology showed diffuse large B-cell lymphoma（DLBCL）. Conclusion Lymphoma should be kept in mind in patients with high pleural effusion ADA levels，pathology examination should be taken in time to confirm diagnosis.

Key words: Key words：Lymphoma, Pleural effusion, Adenosine deaminase