In this paper, we study dust acoustic solitary waves (DASW) based on the dust charge
Zd =equilibrium density of ions / equilibrium density of dust ions , initial dust speed do Udo and initial streaming speed
eo of electrons with the introduction of relativistic effect. Only rarefactive solitons are found to exist in the
unmagnetized dusty plasma in presence of relativity for electrons. It is observed that for greater values of dust
charge Zd rarefactive solitons exist.