This paper explores the synaesthetic metaphors in the Three Hundred Poems of the Tang Dynasty by using the Conceptual Blending Theory. The result shows that, firstly, synaesthetic metaphors is essentially the result of the conceptual integration among different sensory domains; Secondly, the overall trend of sensory transferring of synaesthetic metaphors between English and Chinese is similar, that is, from the lower senses to the higher ones, but the transferring frequency of each sense is different; Thirdly, temperature is the largest source domain while visual and auditory are the largest target domains; Fourthly, poets tend to use “han” (chilly), “liang” (cool) and “leng” (coldness) in the temperature domain and “ku” (bitterness) in the taste domain to express their inner feelings such as sadness, loneliness and depression in their poems.