A one year old baby can’t call mom and dad may be a normal physiological phenomenon, or it may be due to diseases, such as hearing impairment, central nervous system diseases and so on. 1. physiological phenomenon: because each baby’s development will have differences, some babies develop later, a one-year-old baby if in addition to not call mom and dad other aspects of no abnormality, it may be a normal physiological phenomenon, this situation, parents can be appropriate language guidance, usually will improve. 2. Diseases: ① hearing impairment: if the baby itself has hearing impairment, due to the inability to hear the sound, can not stimulate the development of the language system, which will lead to not speak normally. ② central nervous system diseases: such as intracranial tumors, etc., can cause speech dysfunction, resulting in the inability to speak normally as well as pronunciation. When a one-year-old baby has this kind of situation, it is recommended to go to the hospital for relevant examinations and be evaluated and judged by professional doctors.