歷來長於七言古詩之作家，殊不多見。蓋七古體兼雜言，形式多樣，開闔變化，往往莫測。東坡於七古，尤所擅長。本文只就其用韻觀之，已足以見其七古之不同於凡庸也。 中晚唐以來，和詩日多，唯皆和人之作，晚唐自陸龜蒙、韓偓、王周，始見自和之作，三人亦不過各一二首；東坡和人之作不計其數，且其自和之七古，竟超過唐人所作之總和；促起、促收韻，前人多用於五古，而東坡七古亦每用之，且頗流轉；詩中換韻，三百篇已有之，然以四句或八句一換，且必以平換仄，以仄換平之規律化出之，自唐人始，東坡七古換韻之作，必平、仄交遞出之，殊無例外。 鮑照以前之七古，必句句入韻，鮑照始為隔句用韻之七古，自鮑照之後，七古自以隔句用韻為常，唐人偶有逐句入韻之七古，而東坡七古之逐句用韻者，殊不在少。 尤有可注意者，東坡七古押入聲韻諸作，往往將入聲尾之K、P、T 通押。此一現象，適足以說明入聲至北宋已然消失；與一般聲韻學者認為入聲至元代始消失之說法，幾乎提早了上百年，誠然大可注意。此外蘇詩中偶亦可見上去通押或平仄通押之作。 凡此等等，均可見東坡於七古用韻，極盡變化之能事，非大才如李、杜、東坡者，實不足以運之於掌上也。

Su Shih has been one of the greatest writer not only of the Sung Dynasty but also of the whole Chinese literary history. He is a versatile writer capable of writing different ancient style poety, which is one of the most complex styles among all Chinese poetry. This article reviews the rhyming practice of this above-mentioned poety in order to show his great achievement. He is probably one of the first few who use ts’u chi ts’u shou rhyme （促起促收韻）, formally appeared in five-words ku-shin only, in seven-words ku-shin and he is certainly the best one to use this rhyme so smoothly. He likes to vary the rhume, from level to deflected tone and from deflected from level tone alternatively, and every four or eight lines regularly, which is the practice of the T.ang poetry. Something he even composed this poetry with every li ne rhyming, which is the practice of the Han Dynasty. He also composed this poetry with lines that rhyme third tone （上聲）with fourth tone（去聲）；or with lines that rhyme level tone with deflected tone；or thirty-six lines differently with only one line unrhyming. All this variation and innovation of using rhyme in his seven-words ancient style poetry proves Su Shih’s talent as a great poet.