Objective To investigate the significance of lymphocyte positional parameters in screening peripheral blood plasma cell. Methods In total 28 patients with circulating plasma cells, admitted to Changzheng Hospital from May 2019 to April 2020, were selected as research subjects for a retrospective analysis. Meanwhile, 140 healthy individuals who underwent physical examination were selected as the control group. We compared all lymphocyte positional parameters between the two groups. Correlation analysis was performed between lymphocyte positional parameters and the circulating plasma cell percentage, M protein, results of biochemical tests. Results There was significant difference between the plasma cell group and control group for 6 lymphocyte positional parameters(P_LY-X<0.001,P_LY-Y=0.002,P_LY-Z=0.010 P_LY-WX=0.003,P _LY-WY <0.001,P_LY-WZ<0.001). The lymphocyte positional parameters LY-X and LY-WZ had high sensitivity and specificity in screening plasma cell, with the ROC area under curve (AUC) being 0.922 and 0.962, respectively. The pooled AUC of the two indicators was 0.972. And the test had a sensitivity of 92.9% and specificity of 95.9%. LY-Y had significant linear correlation with the IgM(p<0.01). Pearson correlation of 0.817 (n=22,95% confidence interval [CI], 0.60,0.92). LY-Z had significant linear correlation with the circulating plasma cell percentage(p<0.01). Pearson correlation of 0.626(n=24, 95%CI 0.30 ,0.82). Conclusion The lymphocyte positional parameters have been suggested as useful means to screening peripheral blood plasma cell.