Abstract: 【Objective】The effects of chemical fertilizer, organic fertilizer and organic fertilizer combined with application of complex Bacillus sp agent on quality and yield of Citrus reticulata Blanco var.Gonggan and soil fertility under medium soil fertility orchard were studied to provide scientific basis for the improvement of quality of C. reticulata Blanco var. Gonggan and soil fertility.【Method】Three treatments-chemical fertilizer, organic fertilizer and organic fertilizer combined with complex Bacillus sp agent were designed and the soluble sugar, soluble solids, organic acid, vitamin C, single fruit weight and pericarp-pulp ratio of Citrus reticulata Blanco var. Gonggan were compared and analyzed.【Result】Compared with chemical fertilizer treatment, organic fertilizer and organic fertilizer combined with complex Bacillus sp agent could increase the sugar-acid ratio significantly by 3.1 and 3.6，the single fruit weight were increased 10.5 g and 8.9 g significantly while the pericarp-pulp ratio were increased 1.8 and 1.6 percentage poimts.The soil organic matter and alkali-hydrolyzable nitrogen were increased and the average yield were increased by 9.9% and 17.7% in two years. Compared with organic fertilizer treatment, organic fertilizer combined with complex Bacillus sp agent treatment could improve the fruit quality，yield and soil nutrients and increase number of soil bacteria significantly.【Conclusion】Organic fertilizer combined with complex Bacillus sp agent had a significant effect on improving the quality and yield of Citrus reticulata Blanco var.Gonggan and increasing soil microbial quantity.