Tati Dialect of Khalkhal is one of the Iranian North western dialects spoken in shahrood and Xorsh-rostam districts of Khalkhal. Since this dialect has various accents and variants, in this Paper, kajali accent form Xorsh-rostam, and lordi , karini , dәravi , kehali , gilvani form Shahrood are selected to be compared with respect to their ergative characteristics. In the article, at first nominative and accusative cases of nouns and pronouns are described, then, through various examples, the place of pronoun affixes in the construction of some sentences possessing ergative characteristics are indicated, and finally ergative case is described on the basis of its six different forms. Tati Dialect of Khalkhal is distinguished from other dialects producing ergative structures, because of the adherence of verb to semantic object, in number, person and specially in gender. Meanwhile, according to some evidence in this dialect, apart from past transitive verbs, some intransitive verbs are influenced by the ergative structure.