Abstract: A comprehensive trust model was presented mainly for the problems existed in the current assessment of trust degree in online auction. It was a fact that different participants in online auction had different viewpoints on the trust computation, such as recent credibility, time weight, value of the transaction, etc. The assessments of trust degree with multi-viewpoints of different participants being evaluated, credibility of participants was calculated separately. The comprehensive trust model was able to greatly improve the accuracy of calculation. Thus, it is more effective for analyzing the trust degree of the different participants in online auction.