Nowadays, some students in China often use on-line translators when they have to write papers, especially the abstract in English or in Japanese. However, the morphological and syntactic differences in Chinese, English and Japanese frequently lead to problems in translation. The present paper aims at exploring the major morphological and syntactic differences among the three languages and demonstrating how these major differences affect translation rendered by on-line translators. Totally, 8 main differences are identified and illustrated with examples. The study might be helpful for the Chinese users of on-line translators and their developers.