棒球在台灣是相當受到歡迎的運動之一，隨著美國職棒大聯盟在國內的轉播率愈來愈高，使得洋基隊的台灣好手王建民愈來愈受到球迷關注，也因此獲得許多廣告商的喜愛。本研究主要目的是在探討王建民代言可信度與廣告效果之關聯性，透過便利取樣方式進行調查，共計發出問卷350份，回收有效問卷為282份，有效問卷回收率為80.6%，經統計分析後發現：1.消費者對王建民代言之「知名度」感受最高，而在整體「廣告效果」上較不明顯；2.王建民代言之「可信度」與「廣告效果」呈顯著正相關；3.消費者對王建民代言之「專業性」、「知名度」、「吸引力」及「可靠性」感受越高，而「曝光率」感受越低者，其「廣告效果」越明顯；而消費者對王建民代言之「專業性」、「知名度」、「吸引力」、「可靠性」及「曝光率」感受越高，其對廣告效果之「廣告態度」與「產品態度」認同度越高。最後，根據研究結果對業者、後續相關之研究提出建議。

Baseball is one of the most favorite sports in Taiwan. With the broadcasting ratio of Major League Baseball (MLB) events increasing all the more in Taiwan, Chien-Ming Wang, a Taiwanese MLB player, has attracted more and more attention from baseball fans, and has thus become popular among many advertisement companies. The main purpose of this study was to explore the correlation between the credibility and the advertising effectiveness of advertisements endorsed by Chien-Ming Wang. The study has been carried out through a questionnaire survey based on convenience sampling, in which survey a total of 350 questionnaires had been handed out, of which 282 valid questionnaires were recovered. Thus the effective rate of recovery is 80.6%. The following findings had been made based on statistical analysis of the survey data: 1. consumers are most sensitive to advertisements endorsed by Chien-Ming Wang in terms of the popularity of the advertisements but are less sensitive with regard to the effectiveness of the advertisements. 2. There is a significant positive correlation between the credibility and the effectiveness of advertisements endorsed by Chien-Ming Wang. 3. The effectiveness of an advertisement endorsed by Chien-Ming Wang in customers becomes more significant with the increase of the customers' sensitivity to professionalism, the popularity, the attractiveness, and the credibility of the advertisement, and also with the decrease of the customers' exposure to the advertisement. The more sensitive a customer is to professionalism, popularity, attractiveness, and credibility of an advertisement, the more agreeable he/she will think of the advertisement and the product in terms of the effectiveness of the advertisement. Finally, suggestions to advertisement companies were proposed based on the study results, and suggestions for follow-up studies on this issue were also proposed.