Ice growth depression and drag reduction of ice slurries treated with a combination additive of cetyl dimethyl betaine (surfactant) and poly(vinyl alcohol) (PVA) have been investigated. From the results, it is found that the particle size becomes smaller when treated by the present surfactants compared with the corresponding result of each concentration of PVA. Additionally, particle growth depression can be observed due to a cooperative effect of surfactants, even in the case when PVA concentration was reduced to 4 g/l from 8.7 g/l, which was required in the case without surfactants. The present combination additives also cause drag reduction phenomena on the solution. Thus, the combination of surfactants and of PVA could be a promising candidate as additives for improvement of ice slurry fluidity.