Abstract: Objective To explore the predictive value of serum platelet factor 4 (PF4) for the efficacy of new multiple myeloma (MM) patients treated with thalidomide combined VCD. Methods A total of 120 MM patients in Wenzhou Central Hospital from January 2016 to December 2018 were selected as study subjects. All patients were treated with thalidomide combined with VCD for 4 courses, and then divided into reaction group and control group according to the therapeutic response after treatment. The general data, blood biochemical examination and PF4 level of the two groups were compared. Logistic regression was used to analyze independent risk factors for treatment response. ROC curve was used to evaluate the predictive efficacy of different indicators on treatment response. Results Eighty-eight patients (73.33%) responded to the treatment. There were significant differences in ISS grading and Del17p between the reaction group and the control group (P<0.05). The levels of β2 microglobulin and serum creatinine in the reaction group were significantly lower than control group (t=3.841, 2.430, all P<0.05). The level of PF4 in the response group was significantly higher than the control group (t=5.556, P＜0.001). Multivariate logistic regression showed that low levels of β2 microglobulin were independent protective factors for treatment response (OR=0.062, P=0.005), and low levels of PF4 were independent risk factors for treatment response (OR=1.107, P=0.001). The best cut-off points of PF4 and β2 microglobulin for predicting treatment response were ＞736.29 ng/L and ≤3.597 mg/dL, and the AUC were 0.874 and 0.756, respectively. PF4 was significantly better than β2 microglobulin (Z=2.097, P=0.036). PF4 had better sensitivity and β2 microglobulin had better specificity (P＜0.05). Conclusion PF4 has predictive value for the efficacy of new MM treated with thalidomide combined VCD, with the best cut-off points of ＞736.29 ng/L.