The aim of this essay is to present a phonological analysis of Lushai, a Tibeto-Burman language spoken in the Mizoram province of India, in terms of componential features applying ┬Ц as mutation rules ┬Ц to the morphophonological level. An analysis of this nature becomes possible if the concepts of phonological extension systems and redundancy-free representations are introduced. Alongside with the phonemic aspect, a semantic analysis of morpheme structure is required yielding the smallest significant units at different morphological or syntactic levels. Though based on criteria implying concepts like ┬Сrule┬Т, ┬Сunderlying representation┬Т, and so forth, of the standard theory of generative phonology, this essay tries to implement the concepts of ┬Сphoneme┬Т on the phonemic, and of ┬Сmorphophoneme┬Т on the morphophonological levels, and to bring about a methodologically sound classification of phonological rules.