Abstract: Objective To analyze the correlation between the 1q21 amplification and the treatment response in patients with multiple myeloma treated with Bortezomib and/or Thalidomide. Methods Fluorescence in situ hybridization (FISH) was used to detect the 1q21 amplification in patients treated with Bortezomib and/or Thalidomide. The clinical characteristics and treatment response werealso analyzed. Results Results 1q21amplification was discovered in 29 of 108 patients (26.9%). The patients with 1q21 amplification had a higher median age and lower HB concentration than those without 1q21 amplification (62y vs. 58y, P=0.029and81.39 g/L vs. 97.58g/L, P=0.002 ). Other clinical characteristics such as SCr, Ca2+, ALB, β2 microglobulin, plasma cell proportion seemed to have no correlation with 1q21 amplification. The patients with 1q21 amplification had a higher rate of IgH translocation and 13q deletion (79.3%vs. 48.1%，P=0.004 and 58.6%vs. 31.6%，P=0.011, respectively). Thetreatment response was evaluable in 95 patients. The overall response rate (ORR) was 73.7% (70/95).Twelve patients treated with both Bortezomib and Thalidomide were excluded and the remained83 patients were divided into two groups(Bortezomib-based and Thalidomide-based). Response rate was not significant difference between patients with and without 1q21 amplification in Bortezomib-based group, but patients with 1q21 amplification had a higher response rate than those without 1q21 amplification in Thalidomide-based group (70% vs. 80%, P=0.789 and 20% vs. 78.3%P=0.005). Multivariate analysis showed 1q21 amplification was an independent prognostic predictor，OR（Odds Ratio）=0.231（95% CI：0.078-0.684，P=0.008）. Conclusion 1q21 amplification was a vital predictor of prognosisaspatients with 1q21 amplification had a lower response rate when treated with Thalidomide ratherthan Bortezomib.