Using self?report method, this paper explored the perception of the difficulty of Chinese sentences by the students of Korea and Japanese whose Chinese knowledge was at the elementary level, and contrasted the foreign students` perception results with those of Chinese students. The results showed that the students of Korea and Japanese scored lower on two topic?comment constructions than the Chinese students, for these sentence constructions are similar to those of their native languages, so they thought these constructions were easy. But they scored higher on the sentence constructions with Ba and Bei markers than the Chinese students. It was found that the perception of the difficulty of these sentence constructions by the Korean and Japanese students had a close bearing on their native language in typology. The study also found that the self?reporting after language processing was an effective method in the study of second language acquisition. Key Words: self?report, Chinese sentence, native language in typology, perceptional difficulty, language distance