As a high-efficient and a clean energy supply mode

the decentralized energy supply has been developed for many years and many successful applications being realized at abroad. But in China

it is not long after starting

and still in an exploring stage. Combined with problems existing in traditional energy supply systems

the features and advantages of the decentralized ones have been analysed. The operation state of decentralized energy supply systems at home and other developed countries

such as USA

Japan and Europian countries has been analysed in detail respectively. Several problems needing to pay attention in the development of decentralized energy supply systems at present in China have been pointed out.