The stability of two kinds of aggregation states of ethylene vinyl acetate (EVA) copolymer in dilute solution of 1,2-dichloroethane has been investigated by viscometry. It was found that good storage-time, shearing, and dilution resistance were displayed for both states of EVA molecule with intra- and interchain association. And for the pour point depression of wax solution doped with EVA, the EVA in intrachain aggregation state was better than the EVA in interchain aggregation state.