宋、遼、夏三國在中國歷史上的互動關係頗為微妙，彼此都曾有過和平、戰爭，以及在某種情況下，拉攏某一國來牽制第三國的史實。尤其是夏國依賴遼國很深，當它在宋夏戰爭中，處於不利時，所運用的緩兵、求和方式，其中一種是請遼國派遣使節至宋國進行交涉，促使宋國能與夏國恢復和平。
本文即是針對此一方式，詳細論述遼國派遣泛使蕭德崇出使宋國進行代夏求和的始末，包括背景、原因、過程、結果和影響等項目，希望能有助於讀者對宋、遼、夏和戰的互動有進一步的瞭解。

There is quite a subtle and interactive relationship among the Song, the Liao and the Xia countries in the history of China, forming and breaking alliances in the time of war and peace. The Xia country especially relied heavily on the Liao country. When it was at a disadvantage in its war with the Song country, one of the Xia’s methods to stall for time and seek peace was to ask the Liao country to send envoys to the Song country to negotiate, promoting the restoration of peace between the Song and the Xia.
To explore the Xia’s negotiation method mentioned above, this paper discusses the whole story of the Liao’s envoy Xiao De-Chong’s diplomatic mission to the Song country to seek peace for the Xia country in detail, including the background, causes, process, results, and influences. I hope it can help readers to have a better understanding of the interaction and peace and war among the Song, the Liao and the Xia.