In order to accurately measure the value of internet word of mouth (iwom). Based on each attribute of online reviews, which are the major form of iwom, we proposes the influence factors of iwom, include the quantifiable indicators: the number of online reviews, the rating, the proportion of negative reviews, the price of product, and the unquantifiable indicators which can control of the false online reviews and express consumer emotion: the feature words of product attributes, the emotional intensity of reviews. Then we build the model of influence factors of iwom perception. And we take the influence of endogenous into account. Before and after the
control of the endogenous influence, we find that the relationship between influence factors and iwom has changed by using cross section analysis and first order difference analysis.