This paper takes northern China's courtyard ecosystem based on the production of edible mushroom as the research abject. The energy analysis and nutrient balance of a typical peasant household courtyard in the suburb of Shenyang have been studied. The results show that the total exported energy of the products of this courtyard ecosystem is 41 872.14MJ/a. Of them the exported energy of the products of oyste mushroom occupies 65 4%,and the N,P2O5 and K2O of the import export system basically maintain the nutrient balance. It is regarded that this courtyard ecosystem is a highly productive and considerably beneficial system and thus has important realistic significance in directing the construction of the rural courtyard ecosystem in this region.