Objective To explore the relationship between hemoglobin/red blood cell distribution width ra-tio(Hb/RDW)and chemotherapy sensitivity and prognosis in patients with oral squamous cell carcinoma(OSCC).Methods A total of 150 patients with advanced OSCC admitted to the hospital from January 2017 to January 2021 were selected into the study group.150 patients with other oral diseases who were diagnosed and treated for non-OSCC in the hospital during the same period were selected into the control group.Another 100 healthy subjects who underwent physical examination in the hospital during the same period were selected into the healthy group.Patients with OSCC were treated with chemotherapy,and blood routine indexes were detec-ted by automatic blood analyzer,and Hb/RDW ratio was calculated.Hb,RDW and Hb/RDW ratio were com-pared between the two groups and the relationship between Hb/RDW ratio and the sensitivity and prognosis of OSCC patients with chemotherapy were analyzed.The factors affecting the sensitivity of OSCC patients to chemotherapy were explored by multivariate Logistic regression.Results Hb and Hb/RDW in the study group were significantly lower than those in the control group and the healthy group,and RDW levels were significantly higher than those in the control group and the healthy group(P＜0.05).The patients with OS-CC were divided into high Hb/RDW group and low Hb/RDW group using the median Hb/RDW ratio(8.16)as the cut off value.The total effective rate of chemotherapy in Hb/RDW high ratio group was 70.67％,which was higher than that in Hb/RDW low ratio group 53.33％(P＜0.05).According to the sensitivity of chemo-radiotherapy,the study group was divided into sensitive group(n=103)and resistant group(n=47).The proportion of patients with stage Ⅳ,low differentiation and lymph node metastasis in resistance group was higher than that in sensitive group(P＜0.05).Multivariate Logistic regression analysis shows that TNM stage Ⅳ(OR=2.512,95％CI:1.588-3.973),low tumor differentiation(OR=2.237,95％CI:1.427-3.938),lymph node metastasis(OR=2.821,95％CI:1.607-4.951),Hb/RDW≤8.16(OR=3.540,95％CI:2.001-6.261)were risk factors for chemotherapy sensitivity in cases with OSCC(P＜0.05).The 3-year survival rate of OSCC cases in the high Hb/RDW group was 74.67％(56/75)and that in the low Hb/RDW group was 58.67％(44/75),There was a statistically significant difference in the 3-year survival rate between two groups(x2=4.320,P=0.038).Conclusion Hb/RDW is low expression in patients with OSCC,and is re-lated to the sensitivity and prognosis of patients with chemotherapy,which is expected to be a potential mark-er for predicting the sensitivity and prognosis of OSCC.