Objective To explore the clinical features of Kennedy disease .Methods The clinical data of 3 patients with Kennedy disease was respectively analyzed .Results All three patients were middle-aged male and had a chronic onset .Patients were mainly presented with the muscle weakness and fasciculation in the proximal limb and bulbar , and the symptoms grow progressively .Two patients were hyperplasia of mammary glands , 3 patients had high levels of serum creatine kinase , and 2 patients'serum testosterone level was increased .EMG detected a widespread neuronal damage in all three cases , and the sensory conductions were abnormal in 2 patients.Repeat numbers of CAG in exon 1 of androgen receptor gene of 2 patients were tested, and they were 57, 47 respectively.Conclusions The clinical features of Kennedy disease are muscle weakness and androgen insensitivity syndrome in male patient and EMG presented with motor neuron damaged .Repeat number of CAG in exon 1 of androgen receptor gene is increased.