This paper presents the concept of the natural supporting strength.

The initiation of this discipline provides a more massive natural forces theoretical basis for the social economic sustainable development.

Its economic nature is the natural forces economics theory: P=f(N,E), P=2N+3, P=KE aN b, I=E/N .

In fact,however,in a lot of works by Marx,a lot of space is devoted to expounding the relationship between natural forces and productive forces in an all-round way and explicitly advances the scientific proposition that all productive forces boil down to natural forces.

The moveable laws of man-land aystem are controlled by coupling natural force with social force.

Secondly, value is a criterion to the “compensable” consumption of manpower, but the natural force which hides in machinery and replaces manpower is “free”, so the contribution that machinery offers doesn’t create value.

The three sources of economic remainders were: the free supply of natural forces, human intelligence taps natural forces deeply, and the cooperation of production s factors.

Economic fertility of soil is a combined formati on of artificial and natural fertility.

From the ancient myth we can intensely feel the constraint that man transcends the nature, and the will idea and the spirit that man creates existence circumstances.