In a cylindrical mixing tank, several mixing effects have studied with the aid of the dissolution rate constant K induced by Hixon. The solid-liquid mixing system consists of two cases, one contains larger amounts of solid NaCl (180g of NaCl/ℓ of water) compared with those of liquid water. The other small amounts of solid salt (50g of NaCl/22 ℓ of water). For the former, four kinds of agitators are used to compare their agitation charateristics. The mixing effect of the 4-bladed, and the 6-bladed paddle agitators are more excellent than that of the 6-straightly bladed, and the 6-curved-bladed turbine agitator. The mixing effect increases proportionally according to the increasing rpm of agitation. For the latter, three kinds of agitators are used and the mixing effect of the straightly-bladed turbine is better than that of the 4-bladed paddle, and worse than that of the 6-bladed paddle agitator. The influence of rpm of agitation increases the mixing effect in the lower range of rpm, but for the higher speed than 360 rpm, the mixing effect is invariable. And the influences of solid amounts on K values are also researched and compared with a new method for illustrating the mixing effect.