張載一生精思力踐，毅然以聖人之事為己任，凡所議論，率多卓見。朱熹以為其說 多有孔孟未盡者，王夫之更於自題之墓銘中，謂之「希張橫渠之正學，而力不能企」，對張 載之說可謂推崇備至。綜觀張載之卓論，其影響後學甚深者，「變化氣質」之論可謂當其要 。其說以為氣有陰陽、剛柔、屈伸、動靜相互變化，是故氣質之性可以藉由為學之益而突破 質礙，使之化歸於參和不偏之天地至性，呈顯人之主體價值。本文探討張載「變化氣質」之 論，先自宇宙論之立場而言「氣質」之意義。其次，則自其宇宙觀與心之覺知而進入倫理界 ，因而論說變化氣質之必要與可行性。然後，則進入「如何變化氣質」之討論主題，並下分 「以《易》為宗」、「以『禮』為體」之雙線發展，以明其變化之道；前者復由「明窮神知 化之理」與「悟保合太和之道」以言變化氣質，後者則由「體天地之德」、「守定集義」與 「持性、盡性、成性」而說變化氣質。其後，則以法孔孟之人極而論變化氣質之成果。至其 末，則以張載一生之風範作為變化氣質之實證。

　　　　　Tzai Chang was an important scholar who proposed the theory on the change of disposition. He believed that spirit is interwined by two elememts which conceived opposite features: Yin( 陰 )and Yan( 陽 ),hardness and softness, bent and straightens, movement and stillness. He proposed that disposition can be reshaped through self-study. This paper will unflod his theory from different angles. First, the meaning of sprit will be discussed from the perspective of ethics. Finally, this paper will focus on how to improve disposition. In the discussion, understandings of Yi Jing( 《易經》 )and 'Li' 禮 are ways to change a person's personality. Yi Jing allows humanbeings to understand universe which is changeable.'Li' enables us to self-discipline ourselves. 'Li' is the way to maintain, explore your own sprit and finally accomplish the perfection.