Abstract: Composting is an effective way to utilize the resource of garden waste. In order to explore the composting process, the authors studied the change rule of nitrogen and carbon content in different amount of garden green waste composting. The results showed that the total carbon content generally had a declining trend, and the total nitrogen content increased rapidly in thermophilic phase, while increased slowly in low temperature composting phase. Carbon nitrogen ratio decreased in the process of composting. The results of orthogonal test showed that treatments E and H with 800 g sludge added into 1000 g garden waste were advantageous to the composting rotten, which had rational C content of 413.59 and 611.16 g/kg and N content of 17.57 and 21.95 g/kg, and the carbon and nitrogen ratio was 23.54 and 27.84, respectively.