The study examines the effect of different types of animal idioms on the proficiency and comprehension of Chinese EFL learners. In order to analyze the relationship between animal idioms and cultural connotations, a contrastive model for English and Chinese animal idioms is built. Result discussions of an English animal idioms’ test prove that the following points reach significance: (a) the effect of English animal idioms on interpretation; (b) the effect of English proficiency level on the comprehension of English animal idioms; and (c) the fact that L2 proficiency level and animal idiom types interact with each other.