Abstract: A composting experiment was carried out, using fixed proportion of swine manure, increasing proportion of eucalyptus bark and decreasing proportion of banana stem, to explore effects of ingredient ratio and C/N ratio on composting temperature, pH, number of microorganisms, seed germination rate and some other composting fermentation indexes, and followed by a pot experiment to test the effects of composts different in ingredient ratio on growing of banana seedlings. Results show that when C/N of the composting material was 25.24 or 27.01, the heaps of compost were the highest in temperature, reaching up to 56 ℃ or higher and maintained the high temperature for 10 and 11 days respectively, and they were also higher in content of nutrients, and up to the criteria of the national standard (NY 525—2012) for organic manure, The pot experiment also shows that composts out of the two formulas had a certain growth-promoting effect on banana seedlings.