Objective:To investigate the dignosis and treatment of familial medullary thyroid carcinoma in order to provide basis for its early diagnosis and treatment.Methods: We summarized the clinical data of familial medullary thyroid carcinoma,and combined with literature to investigate its etiology,early diagnosis and treatment.Results:Familial medullary thyroid carcinoma is aeuchromosome obvious syndrome arosed by RET break.It is bilateral and many focus,and mostly is young blood;Reasonable operation can get satisfactory result in the treatment for familial medullary thyroid carcinoma.Conclutions:FMTC is a kind of hereditary diseases;there is satisfactory result when early diagnosis and reasonable operation are applied.Follow-up survey of family members should be performed in a long period of time.