This thesis is intended to study the preposition “for” under the theoretical framework of image schema,with metaphorical extension.Through the data analysis of gap filling,translation between English and Chinese,and retrospective interview,the writer concluds that 1) Chinese learners don’t have good comprehension of the preposition “for”,including its extended meaning; 2) The preposition “for” easily causes confusion with the preposition “of” ; 3) When using the preposition “for”,Chinese learners may be influenced by the transfer of their native language.The cognitive study on the preposition “for” will play a practical role in preposition teaching and learning.