Abstract: This study was conducted to quantify the impact of different fertilizer amounts on the growth and fruit quality of mulberry. A field experiment with treatments of different fertilizer amounts at germination stage was performed and single fruit weight, yield per plant, new shoot, soluble solids, as well as hydrogen ion concentration index of seedless ‘Big Ten’ mulberry were determined. Membership function formula of fuzzy mathematics was used to compare and explore the best fertilizer amount which could improve the growth and fruit quality of mulberry. Result showed that fertilizer amount had no significant effect on hydrogen ion concentration, but it could improve mulberry growth and fruit quality. Along with fertilizer amount increasing from 100 g to 150 g per plant, the single fruit weight, yield per plant, and soluble solids increased by 23.51%, 26.69%, and 39.63%, respectively. However, new shoot growth and hydrogen ion concentration index had no significant difference. Additionally, no significant difference of new shoot growth, hydrogen ion concentration index as well as soluble solids of mulberry was found between fertilizer amount of 100 g and 150 g per plant. When fertilizer amount increased from 150 g to 250 g per plant, the yield per plant increased by 8.32%, while the soluble solids decreased by 18.60%. According to the analysis of membership function, appropriate fertilizer amount of mulberry was 150 g per plant.