The purpose of this paper is to study the correlation between the perfective aspect and the negation of serial-verb constructions in modern Chinese. For methodology, the distribution patterns of “了, ” a perfective aspect marker that appears at the back of verbs to represent the completion of action or changes of events, were analyzed. The results of the analysis have revealed that, as more than two verbal phrases are continuously used in a serial-verb construction, the perfective aspect marker “了” not only shows various distribution patterns but also changes the meaning of a sentence according to its location. It has been also revealed that the negative adverb “沒(有)” appears only in front of VP1 when it is used to express a negative meaning in serial-verb constructions. In other words, the distribution pattern of the perfective aspect marker “了” is asymmetrical with that of the negative adverb “沒(有)” in the serial-verb constructions of the modern Chinese language.