Objective To explore MRI performance of malignant tumor of tongue base (tongue base carcinoma) and diagnostic value. Methods A retrospective analysis of clinical data was carried out in 28 patients with tongue base carcinoma confirmed by operation and pathology treated in surgical oncology of our hospital from January 2010 to May 2015, all clinical data underwent MRI plain scan and enhancement scanning, a retrospective analysis of MRI performance of patients was carried out to explore diagnostic value of MRI in tongue base carcinoma. Results MRI showed that there were 15 cases of left side tongue lesions, 8 cases of right side tongue lesions, 5 cases of middle side tongue lesions; sensibility of tongue base carcinoma T staging results 85.71% was significantly higher than sensibility of clinical stages (64.29%) (P<0.05), there was no significant difference in maximum diameter measurement MRI measured value (3.52±0.41)cm and sample measured value [(3.45±0.41)cm] (P>0.05), incidence of lymphatic metastasis when MRI tongue base carcinoma maximum diameter ≤2cm was significantly lower than that when maximum diameter >2cm (P<0.05), which suggested lymphatic metastasis was closely relative to maximum diameter of primary lesion showed in MRI. Conclusion MRI can be preferred method in the diagnosis of tongue base carcinoma, MRI has implications for detecting lymphatic metastasis in tongue base carcinoma, clinical diagnosis value is higher.