This thesis quotes six important confucian ancient classics: “LUN-YU” [論語], “MONTSU” [孟子], “HSUN-TSU” [荀子], “SHU-CHING"[書經], “YI-CHING” [易經] and “CHUNG-YUNG”[中庸] to interpret the environmental thought of confucianism. Through the explanation of these classics, we have reached the following conclusions: 1. The Confucian's realization to the environment is neither meditation (mystic thought) or religious reflection nor the science which is to pursue “Logos” and “Pure Form”, it is the interpretation of “Human World” after reasonable and empirical observation on the Great Nature with a view to “Govern the World”. 2. Fundamentally, the Confucians regard the natural environment as a “environment of vitality”, in essence, it holds and possesses the function of “multiplying endlessly and moving continuously to and fro” and this function is perpetual, ever-lasting, enormous and infinite. 3. Two divinations, “CHIEN” [乾] & “KUN” [坤], of “YI-CHING” [易經] and the conception of “CHENG” [誠] of “CHUNG YUNG” [中庸] is exactly the ontological basis of the Confucian's recognition to the natural environment-“SHENG SHENG CHIH TE” [生生之德] (multiplying endlessly). Confucians hold the Great Nature internally and superiorly has its creative and developmental innate source of energy, i.e., “CHIEN YUAN” [乾元], “KUNYUAN" [坤元] or synthesized as “CHENG” [誠] or concluded to be one – “TIEN TAU” [天道] (Heaven). Since “TIEN TAU” may develop by itself, there shows out the vital and energetic Great Nature Environment-multiplying endlessly and moving continuously to and fro. 4. Facing this environment of spring vitality, Confucians particularly treat it in the manner of “Cosmic order” and “Moral Order” established by “Moral Metaphysics”, pursuant to this, there are “JEN” [仁] (or “CHENG”), i.e., “Moral Reason” or”Moral Humanism” to lead to the thought of “joining and helping the creative life of Great Nature”, from which the great Confucians, Mon-tsu & Hsu-tsu, construct their theory of “WANG TAU” [王道] – “Going into the woods in the right time”, then the people will get the sufficient food, a ap-pliances and wood materials, and thereof there will be no regret for being alive or died.