Dust acoustic (DA) solitary waves are investigated in an unmagnetized dusty plasma comprising of fluid warm dust particles and kappa distributed ions. We assume the electron number density to be sufficiently depleted in this fluid model, i.e., ne<kcrit , otherwise overdamping occurs. The critical value of the wave number increases withn , while it decreases withk . Also, a modified Korteweg-de-Vries (mKdV) equation was derived for description of DA solitary wave. We found that the amplitude, width and velocity of DA solitary waves are modified in the presence of damping term. As the amplitude and velocity of solitary DA wave decreases with t, the width of soliton spreads. Also, it is found that the polarity of soliton changes from positive to negative at special value of k.
