无主语分句在书面英语中出现的频率很高。由于无主语分句本身不含主语，所以必须准确判断无主语分句的逻辑主语才能正确理解无主语分句的完整含义。本文通过大量例句分析了不定式分句、分词分句和无动词分句等三种无主语分句的逻辑主语 No clause is spoken frequently in written English. Since the clause without the subject itself contains no subject, it is necessary to accurately judge the logical subject of the clause without the subject to correctly understand the complete meaning of the clause without clause. In this paper, a large number of sentences are used to analyze the logical subjects of three unclame clauses, such as infinitive clauses, clause clauses and non-verb clauses