More and more e-commerce's issues are studied in these days, especially for the price promotion. Due to customers have different thinking process; their perceived value is different too. Some researches study the impact of consumer behavior by price promotion type or frequency, yet these researches seldom examine the mental processing before purchase decision making by the promotion factors. Mental simulation can be used as a heuristic for estimating probabilities or assessing causality. Therefore, based on the perspective of consumers' heuristics, this paper fills that gap by focusing on the impact of e-commerce's price promotion on perceived value.