訊號理論主張消費者購買有形產品會由各種內、外部線索，進行購買決策評估，惟服務無形特質，致使服務消費充滿不確定性與風險下，仍未有學者針對服務保證、價格與企業可信度進行服務業之相關研究。因之，本研究乃欲探討服務保證、價格訊息與企業可信度對消費者購買意願之影響，並檢測企業可信度是否會對上述變數間之關係產生干擾效果。本研究以實驗法為研究方法，設計二種服務保證（有／無）、二種價格（高／低）、二種企業可信度（高／低），探討其與購買意願之關係。分析結果發現，在有服務保證且低價格與高企業可信度之情況下，消費者之購買意願最高，而低可信度之企業在提供服務保證後，消費者之購買意願雖仍不及高可信度之企業，但是提升購買意願之效果卻較高可信度企業來得更高，可見企業可信度亦具干擾效果存在。

Signal theory address an issue that consumer would purchase physical products through intrinsic and extrinsic cues on their decision making. However, because of service's intangible characteristic, services are typically regarded as a riskier purchase than a physical product, but has not been discussed in depth in the area of service industry. Therefore, the purpose of this study is to investigate the moderating effects of corporate credibility on the relationship between service guarantee, price information on purchase intention. The study used experiment method to examine a total of eight experiment cells, combination of 2 guarantee types, 2 price levels against 2 corporate credibility levels being the factorial design to assess the impact on purchase intention. The result showed that corporate credibility has significant moderate impact on purchase intention. In turn, when corporate credibility is high, price low level and service guarantee, the purchase intention highest.