Onomatopoeia is derived from the ancient Greek word Onomatopoiia. In Japanese, Onomatopoeia are divided into 'Ni Sheng Ci' and 'Ni Tai Ci'. In Chinese, Onomatopoeia are divided into 'Xian Sheng Ci' (Ni Sheng Ci) and 'Xiang Tai Ci' (Ni Tai Ci). This paper respectively compares and analyzes Onomatopoeia of Chinese and Japanese from the perspectives of the lexical form, lexicality and grammatical function.