The relationship model between instrumentality of WOM information source and various personal influencing factors were provided and empirically tested The motivation to search and self efficacy related to WOM information search as mediating factors were examined. Form the empirical search , it was shown that motivation to search and self efficacy have the positive effect on the instrumentality of WOM information source, and the innovation have negative effect on ones. It was verified that prepurchase involvement, need for cognition have positive effect on the self efficacy. And the positive effects of the subjective knowledge and innovation need for cognition are verified but the motivation to search not.