吉川幸次郎以為中國文學的特質在於抒發內在的情感，描寫生活環境的現實，至於忠實於文學的傳統，窮究於美善境界的追求，既要求表現技巧的緻密，又重視內在感受的飛躍是中國文學作品美善圓熟的終極。中國傳統文學上下三千年的歷史即在此理念下展開，而將「緻密」而「飛躍」之文學理念表現於極致的是杜甫。於是終其一生以致力於杜詩的研究，可謂是杜甫千載之後的知己。

Yoshikawa Cohjiro assumed that the characteristics of Chinese philosophy were expressed the inner emotion, and described the reality of surroundings. It was faithful to confucian orthodoxy and devoted to ambition of beautiful confines. The demand of detailed idiosyncrasy and the leap of respected inner emotion were the ultimate of mature Chinese philosophy. For this ideal, the traditional Chinese philosophy was began before thirty hundred years. To devoted to the detail and leap of ideal philosophy was Tu Fu. Yoshikawa Cohjiro researched in the poems of Tu Fu all his life, so we can say he was an intimated friend of Tu Fu.