A field trial was carried out to study the influence of nitrogen (N) and phosphorus (P) combined fertilization to mulberry growth and leaf yield.The results showed that suitable N and P application rate ratio significantly improved mulberry growth.Branch number,branch length and diameter increased with N and P application rate increase.It was showed that treatment N_(450)P_(150) harvested the highest leaf yield with more 5139 kg/hm~2 than other treatments and increased yield by 22.4%.The result indicated that the optimum NP_2O_5 application ratio was 31 at N rate of 450 kg/hm~2.The study demonstrated that there was positive interaction between N and P on mulberry leaf yield and high N applied rate need adequate P application.