Objective :To investigate the imaging features of metaplastic breast carcinoma by grayscale ultrasound , color Doppler ultrasound and ultrasound elastography .Methods :Imaging data of metaplastic breast carcinoma of twenty cases proved by pathology were retrospectively analyzed .Results :There were eighteen masses with hypoecho and 2 masses with medium echo .Ten masses showed heterogeneous echo and the other ten showed homogeneous echo .The shape was irregular in 13 masses ,oval in 4 masses and microlobulated in 3 masses .The margin was circumscribed in 15 masses and indistinct in 5 masses .Microcalcifications were found in 6 masses .Echo free space was found in 9 masses .There were 18 cases with posterior acoustic enhancement , one case with invariable posterior echo and one case with posterior attenuation . Hypervascular , isovascular ,and avascular masses were found in 14 ,4 ,and 2 cases ,respectively .The mean resistance index was 0 .77 .Four masses were examined by ultrasound elastography .One mass was scored as 3 and 3 masses were scored as 4 .The accuracy rate of ultrasonic diagnosis for breast mass was 85% (17/20) .And the accuracy rate of ultrasonic diagnosis for ipsilateral axillary lymph nodes was 75% (3/4) .Conclusions :Irregular shape ,posterior acoustic enhancement ,cystic spaces ,microcalcifications , hypervascular mass and high elastography score are the most frequent ultrasonic features for metaplastic breast carcinoma .The combination application of grayscale ultrasound ,color Doppler ultrasound and ultrasound elastography may be conducive to the etiologic diagnosis of lesion .