《易﹒說卦》所謂「參天兩地而倚數」學者皆知其內涵當與益占之數相關，唯於「參天兩地」之具體含義，則歷來解說不一，又多牽涉《易﹒繫》「天地之數」及「大衍之數」為義，後學往往莫知所從。本文先就本章章旨論定其內容性質，進而檢討漢宋學者最主要的幾家注解，析論其得失所在。認為漢代馬融、鄭玄之說嫌於簡略不完，致使後人不易掌握，唯推究其義，似非絕不可通。韓康伯、孔穎達以下，以至朱熹，不滿前說，皆易發新義，而轉不可恃。本文復揭示漢人另一解讀的可能，即本近人李笠的意見，以為「參天兩 地」與「參天貳地」同義，「參」、「兩」非數字，而是比擬、副貳之意。本篇綜合先秦兩漢古籍資料，對其訓義進一步加以論證闡明，以求可能適切的義解。

Itis widely known by scholars studying the Book of Changes that the sentence “Santian liang di er yi shu (The number 3 is assigned to heaven， 2 to earth， and from these come the (other) numbers)" in the chapter “Shuogua(Remarks on the Trigrams)" is closely connected with the numbers of divination. Throughout the history， however， there have been numerous explanations for the concrete idea of “santian liang di." Since most explanations involve “tiandi zhi shu (the numbers ofheaven and earth)" and “dayan zhi shu (the number ofthe Great Expansion)" mentioned in the chapter “Xicizhuan(Explanationof the Trigrams)，\" this phrase is difficult for leamers of the Book of Changes to understand. This paper firstly determines the phrase's meaning based on the main idea of the whole chapter and analyses the most important annotations made by scholars in the Han and Song Dynasties. Ma Rong and ZhengXuan's theories are too simplified to make people understand， but they still have some advantages. Later scholars like Han Kang-Bo， Kong Ying-Da and Zhu Xi are unsatisfied with their previous theories， so they create new explanations of their own， which tum out to be too weak: to refer to. Li Li believes that“san tian liang di" is actually “cantian er di，\" meaning “totally with the numbers of heaven and earth." By examining ancient written records in the pre-Qin and Han Dynasties， this paper concludes with the appropriate explanations of “santian liang di".