Humor, as a universal language phenomenon, is an important part in people‟s daily life, which can improve human relations, bring pleasant feeling to people. A sitcom, short form for a situation comedy, consists of a large quantity of humors, and is one of the best carrier forms of humor. Friends is one of the most successful American sitcoms. Love Apartment also enjoys great popularity in China. Under the theoretical framework of speech act theory, this paper analyses the similarities and difference of humorous speech acts in these two famous sitcoms and explores the reasons behind the difference and aims to help the audience have a better interpretation of the sitcoms.