More and more overseas and Chinese scholars have rediscovered the scientific and practical values of the ancient Chinese ideas on Man-Land relationship when the life-supporting environment of human beings is facing the enormous challenges now. From the view of modern Geography, the concepts of "heaven" and "earth" in ancient China may be interpreted into "climate" and "land" which equals to the natural environment. The ancient Chinese ideas on Man-Land relationship aim at the harmonious between man and nature. Its main views may be summed up in to following three aspects:1) To accept the restriction of environment to human beings. This was the base for the establishment of the ancient Chinese ideas on Man-Land relationship. The restriction was made from two aspects. One was the essential restriction of the climate (heaven) and land (earth) to the food production, which acted as the base of the Chinese civilization. Another was the vulnerability of natural system to the impacts of human activities. 2) To claim on th e active adaptation on the premise of obeying the natural rules. The adaptation in ancient China included acclimation and resistance. As a simple and effective means of adaptation, active acclimation aimed to obtain the maximum benefit from the nature with minimum input based on the understanding to the nature. Instead of conquering the nature, resistance aimed to mitigate the damage from the nature or even to reverse damage to benefit by actively struggling against the negative impacts of the nature, which even emphasized the positive activities of human beings. 3) To protect the natural environment for the sustainable development of human society. This may be regarded as the forerunner of the modern eco-economic ideas. Protection on the farmland and natural balance were in the highest priority in order to ensure sustainable utilization of the natural resources. These ideas formed in the long history of China, compose an important part of the tradition of Chinese cultures. The modern society may benefit from the ideas.