As an important motivation theory, a lot of researchers pay attention to Regulatory Fit Theory (RFT). Past studies have shown that regulatory fit had an impact on attitudes and behaviors, such as motivation (Hong & Lee, 2008), emotion (Idson,et al., 2004), persuasion (Zhao & Pechmann, 2007), negotiation (Gross & Appelt, 2008) and leadership (Stam, et al., 2010) etc. Recently, some scholars began to apply RFT to one of new areas---decision making, also had many useful findings. However, integration studies related to RFT and decision making were scarce. Therefore, this paper tried to explore the regulatory fit effect and its mechanism in multi-attribute decision making. Payne et al. (1993) thought that multi-attribute decision making was a process related to information processing and search, decision makers often use two information search patterns: based on attribute and based on alternative. Then whether promotion focus and prevention focus participants have different preferences on information search pattern? Whether regulatory fit occurs between regulatory focus and search pattern? Finally lead to regulatory fit effect? In addition, studies involve non-decision making indicated that processing fluency was the mechanism of regulatory fit effect, if it involves multi-attribute decision making, can we gain same conclusion? In order to answer above questions, eighty six undergraduate students participated in the experiment, among which six students didn’t complete the experiment, and their data were deleted. This experiment employed 2(regulatory focus: promotion focus/prevention focus) × 2(information search pattern: based on attribute/based on alternative) between-subject design, Participants were randomly assigned to four experimental conditions. Every condition included 20 participants. The dependent variables were evaluation of the chose option, processing fluency in decision making. In this study, Participants were first asked to complete regulatory focus priming task as well as correspondingly checking measures. After that, participants were requested to complete multi-attribute decision making task and correspondingly checking measures. Finally, they completed questionnaires about post-decision evaluation and processing fluency. All experiment data was analyzed by SPSS15.0. The results of the experiments indicated that: (1) based on attribute search pattern was found to be used more frequently under promotion focus, whereas based on alternative search pattern was used more frequently under prevention focus; (2) regulatory fit between promotion/prevention focus and based on attribute/ alternative search pattern was found in decision making, moreover this fit made participants give more favorable post-decision evaluation to their chosen option, in other words, regulation fit effect occurred in decision making; (3) processing fluency could be used to partly explain this regulation fit effect. These findings added to the current knowledge on regulatory focus theory by exploring different preferences between promotion focus and prevention focus on information search pattern in decision making. In addition, our results enriched theoretical and empirical studies involved regulation fit theory, meanwhile contributed to understanding of mechanisms underlying the regulatory fit effect. Future research was needed to explore the relationship between processing fluency and feeling right, finally revealed the true mechanism of regulation fit effect.