For this study, two experiments were conducted. Experiment 1 examined the extended benefit at market weight if pigs were supplemented with high level phytase from early nursery. Experiment 2 aimed to clarify varied levels of phytase in P balance in nursery pigs. Exp. 1 showed that pigs fed 12500 U/kg phytase in a deficient P diet (0.13% aP) during both the nursery (Trt. 4) and nursery-growing (Trt. 5) phases had full recovery on overall gain weight from adequate P (0.35% aP), and also can reduced P excretion by 70.79% and 64.60% in the nursery phase when compared to positive controlled (P<0.0001). An LP diet with 250, 500, 2500, and 12500 U/kg phytase reduced fecal P (%) by 21.76%, 16.67%, 39.81%, and 49.54% (P<0.0001) when compared to HP without phytase supplementation. The results indicated that a high level E. Coli. phytase has a sustained benefit on growth performance, and bone strength in growth-finishing pigs and that 2500 and 12500 U/kg phytase could reduce P and Ca excretion efficiently in nursery pigs.