Chinglish is what occurs when the Chinese language and English language crash into one another.When native Chinese speakers who are learning English attempt to directly translate Chinese into English,using Chinese sentence structure,wording and grammar,a blend of Chinese and English happens.Among Chinese English teachers and English as a second language (ESL) foreign experts working with students,this phenomenon is commonly referred to as Chinglish.In order to help students to overcome Chinglish in their oral English and cultivate their sensibility of foreign culture and mode of thinking the awareness of the causes of Chinglish is a must.This paper focuses on analyzing the causes in terms of negative transfer of mother tongue and the differences between modes of thinking and cultural backgrounds.