With the surge in the number of the online review, how to get valuable information from a large number of useless information become a new problem that people face with when they shopping online. So far, many scholars have carried on some researches on this problem, but most of the studies were based on tangible goods' online reviews, and studies about services' online reviews are still very few. This research-in-progress aims to apply the ELM (Elaboration Likelihood Model) analysis framework to develop the model of customer review helpfulness from the perspective of cognitive theory. We plan to carry on empirical research on the review data of service from Dianping.com, and test the model presented in this paper according to the theoretical analysis.