Objective: This study aims to investigate the correlation between cytogenetic detected by fluorescence in situ hybridization (FISH) and the patients’ clinical features in chronic lymphocytic leukemia (CLL), to analyze the prognostic value. Methods: Total 74 cases of chronic lymphocytic leukemia patients were collected in Nantong University Affiliated Hospital from June 2013 to October 2020, with 74 cases of newly diagnosed patients, 43 males and 31 females. The clinical characteristics of patients, laboratory tests, bone marrow smear results, immunological typing results, FISH results and other information were collected. The correlation between cytogenetic abnormalities and gender, age, the clinical Binet staging , Rai staging and the related laboratory examinations including peripheral blood 1ymphocyte absolute count, hemoglobin, platelets, lactate dehydrogenase (LDH) , β2-microglobulin(β2‐MG) were analyzed. Results: ? Cytogenetic abnormalities were found in 56 of 74 CLL patients (75.68%). ?There was no significant relationship among the cytogenetic abnormalities and the sex, age, peripheral blood lymphocytes, hemoglobin, platelet, β2-MG, LDH expression level (P>0.05). ?In the case of Binet stage, chromosome 12 (+12) was only detected in stage B and stage C , and the differences were statistically significant（?2=4.696，P=0.041） ; The survival time of group C was significantly shorter than that of group A and group B. In the modified Rai stage , the deletion of ATM gene were only detected in the high risk group , and this distribution difference has statistical difference (?2=5.40，P=0.000). The survival time of the high risk group is shorter than that in the low and medium risk group (?2=12.393，P﹤0.001). The survival time of CLL patients with simple del (13q) karyotype abnormality was significantly longer than that of patients with complex karyotype (?2=8.138，P=0.017). Conclusion: CLL is an inert disease, but its disease progression and clinical prognosis are highly heterogeneous. FISH test results combined with disease clinical staging can better predict the prognosis.