This work was conducted to investigate the effect of dietary phytase on growth performance and excreta excretion of growing-finishing pigs for 7 days. Eighty three crossbreeds (Yorkshire ${ imes}$ Landrace ${ imes}$ Duroc) of growing-finishing pigs were used in this work, and divided into 6 treatments. Six treatments were compared in a $2{ imes}2$ factorial arrangement with 2 groups (5 replications/group, 8 head/replications) with the additive phytase and 3 groups(growing I, II and finishing phase) with growing phases. Initial weights with growing phases were $58.6{pm}3.9$. $83.2{pm}3.8$ and $111.4{pm}5.4kg$, respectively. Body weight gain was high in phytase treatment (P<0.01) and low at finishing phase. Feed conversion ratio was high in no phytase treatment and at finishing phase (P<0.05). Feed and water intakes have no significant difference with phytase existence and growing phases. Feces excretion decreased with growing phase (P<0.05), and was low at phytase treatment (P<0.05). There was no significant difference on urine excretion (P>0.05). Nitrogen (N) and phosphorus (P) intake was not found significant difference with phytase and growing phases. N excretion had no significant difference on phytase existence and growing phase (P>0.05), but P excretion decreased at phytase treatment (P<0.05). N and P excretion ratio was low at phytase treatment (P<0.05). Finally, dietary phytase resulted in improvement of growth performance and reduction of excreta excretion of growing-finishing pigs.