近年來，台灣許多縣市的住宅價格不斷高漲，身為政經重鎮之台北市首當其衝，於2008~2009年金融海嘯時期，政府為維持經濟發展而全面將遺產及贈與稅調降為單一稅率10% 後尤然。以產品價值而言，此波上漲很可能來自於「逢低買進，逢高賣出」之投資心理造成。由於不動產最終用途為使用，當真實需求者無力負擔時將導致房市泡沫，更因房市的經濟佔額高，進而可能引發經濟泡沫。為檢視台北市住宅價格的合理性，鑒於出租住宅需求者動機單純，本文以租價關係探討台北市住宅價格是否已有偏離實際使用需求之現象；且是否因未來的住宅價格在預期之引導下，使房價似遵循著過去價格的成長而逐步提高，有不效率之現象。實證結果顯示，台北市住宅價格與租金間已然背離，在金融海嘯過後種種非理性現象更為嚴重，導致房價有偏離其合理結構之虞，成交總價越高的住宅、偏離情況越為明顯，而存在泡沫化危機。 / In recent years, the housing market has been awash with funds. The phenomenon resulted in domestic housing prices in Taipei rising year by year, especially after the Subprime mortgage crisis. From the viewpoint of economics, the price is decided by supply and demand. However, with regard to the value of product, this rising of housing price probably comes from the artificial demand. In other words, this kind of demand is just like "buy low and sell high". In addition, real estate is a special commodity, except as an investment good, it is also a necessary consumption good. Furthermore, real estate is expense, making housing the biggest item among households’ assets. Once housing price is too high and the actual demanders cannot burden with; that is likely to trigger a market bubble, which caused the imbalance of trade market. According to the aforementioned, this study will observe whether the housing price has deviated from the fundamentals in Taipei City. Since the demand of rent is only for living, we probing into the relationship between housing price and rent in order to observe the rationality of housing price; and if the future housing price in the anticipated guided, the price seems to follow the historical trend, and the higher the housing price of an area, the more significant. The empirical results show that, the housing price seems to prevail in unreasonable investment in Taipei City, which may lead into a bubble crisis.