程頤的易學專著是《易程傳》，本文欲論述的即是程頤在其中呈的誠信觀點。誠和信是修養工夫，經由內心的鍛鍊以至於儀式、人際互動的實踐。在日用倫常「信」的表現上，分列修身、齊家、治國和祭祀四方面敘述。

In the Sung dynasty, many thinkers mentioned the concept of cheng (integrity,誠) and xin (honesty,信), including Cheng Yi程頤. Following forerunners discussion, Cheng Yi also studies the importance of the concept of cheng and xin and presents his thought in Yi cheng zheuan 易程傳, his very famous philosophy. This book serves the concept of cheng and xin well through twenty six Gua (trigram, 卦). Cheng Yi thinks xin is included in Cheng. Cheng is the noumenon, and if we can emphasize our cultivation, then make into practice to our society, it also means we act xin. In this memoir, I will show how Cheng Yi provides his vision about the concept of cheng and xin, and generalize his methods to cultivate oneself to be a sage.