The study of exceptional set has a history of half a century. In reference ( 2), Lento extended the famous Picard Theorem and Presented the concept of exceptional set of entire functions and meromorphic functions. 例外集问题的研究,已有半个世纪的历史,在文献〔2〕中,Lehto推广了著名的Picard定理,并首次提出例外集的概念,在他的结论中,例外集为一无穷复数序列。