The peripheral blood mononuclear cells of healthy volunteers （control group， 50 cases） and DLBCL patients （DLBCL group， 100 cases） were collected and extracted，and the human B lymphocytes and OCI-LY7 cells were cultured at the same time. The expression levels of SOCS3 mRNA in peripheral blood mononuclear cells， B lymphocytes，and OCI-LY7 cells of the subjects in two groups were detected by real-time fluorescence quantitative PCR （RT-qPCR） method. The OCI-LY7 cells were divided into pcDNA3.1-NC group and pcDNA3.1-SOCS3 group， and the cells were transfected with pcDNA3.1-NC and PCDNA3.1-SOCS3， respectively.The expression levels of SOCS3 mRNA in the cells in two groups were detected by RT-qPCR method；the EDU positive cell rates of the cells in two groups were detected by EDU experiment， and the microtubule-associated protein 1 light chain 3（LC3） positive cell rates in the cells in two groups were detected by cell immunofluorescence staining； flow cytometry was used to detect the apoptotic rates and the percentages of cells in different cell cycles in two groups，and Western blotting method was used to detect the expression levels of SOCS3， phosphorylated Janus kinase 2（p-JAK2） and phosphorylated signal transducer and activator of transcription 3 （p-STAT3） proteins in the cells in two groups.The ratios of LC3Ⅱ/LC3Ⅰ was calculated.

Compared with control group， the expression level of SOCS3 mRNA in peripheral blood mononuclear cells of the patients in DLBCL group was decreased （P<0.01）； compared with B lymphocyte group， the expression level of SOCS3 mRNA in the OCI-LY7 cells was decreased （P<0.01）. Compared with pcDNA3.1-NC group，the expression levels of SOCS3 mRNA and protein in the cells in pcDNA3.1-SOCS3 group were significantly increased（P<0.01）， the EDU positive cell rate of OCI-LY7 cells was significantly decreased （P<0.01）， the ratio of LC3 Ⅱ/LC3Ⅰ and the number of LC3 positive cells were decreased significantly（P<0.01），the apoptotic rate of OCI-LY7 cells was significantly increased （P<0.01）， the percentage of cells in G₀/G₁ phase was significantly increased （P<0.01）， the percentage of cells in S phase was significantly reduced （P<0.01），and the expression levels of p-JAK2 and p-STAT3 proteins were significantly reduced （P<0.01）.

SOCS3 is lowly expressed in the peripheral blood mononuclear cells and OCI-LY7 cells of the patients with DLBCL. Overexpression of SOCS3 can inhibit the proliferation and autophagy of OCI-LY7 cells， and enhance the apoptotic rate， and its mechanism may be related to inhibiting the JAK2/STAT3 signaling pathway.