本文採用「現地研究法」，為姜夔〈過垂虹〉一詩提出精確的詮釋。〈過垂虹〉只是二十八字的小詩，本文通過對「蘇州至湖州」古代水路的現地研究，明確的指出姜夔的旅行實況。筆者先從三十種元明清的路程書，取得水路沿途地名；再以四十種宋明清的旅行日記，來驗證這條水路的實際航行經驗。GPS數據方面，以Google Earth Pro為基礎，以天地圖與谷歌地圖為對照，將民國早期所測繪的本區內五萬分之一地形圖與一萬分之一地形圖全部數位化，再輔以2017年7月親自現地考察，取得這些全部可以複驗的第一手數據，將使姜夔的旅行，除了文學之美，更有回復宋代現地的真相之趣。

Employing the on-site study method, this paper researches the ancient waterway from Suzhou to Huzhou, and then proposes a precise interpretation of Jiang Kui’s poem ‘Passing Through Chuihong Bridge’, a Seven-Character Quatrain, and lays bare Jiang’s journey. Firstly, this paper finds out the names along the waterway from 30 journey books in Ming and Qing Dynasties, and then verifies the actual traveling experience of this waterway according to 40 traveling notes in Ming and Qing Dynaties. In terms of GIS, based on Google Earth Pro, this paper compares the Map World with the Google Map, and digitalizes the topographic map of this waterway with a scale of one out of 5,0000 and with that of one out of 1,0000 which were both drew in the early times in Republic of China. All the first-hand and verifiable data collected during my on-site study in July, 2017, apart from unveiling the literary beauty of Jiang’s poem, also discloses the truth of the on-site situation in Song Dynasty.