After the definition of the economy and its different types, we have to stress the political economy which integrates pure economy and society. The economical science will gradually introduce the health economy of which the definition urges to seek for a better distribution between public and private means to do more and better for the public health. The market economy is different from the state economy. She is principally conducted by the supply and demand law. The consumer's behaviour in a competitive market has some characteristics which favour the balance of this market. The healthcare market put also a health supply and demand forward but not with the same values. The needs, the supply, the consumption and the consumer's behaviour are different in this particular market which quickly evolves and progressively goes closer to the market economy. Is the healthcare an economical good or duty? The choices' criteria and the priorities are changeable. The role of the valuation studies in health economy is to try to clarify them and to favour a better use of the limited resources to the unlimited needs.