Abstract: Abstract： The experiments were conducted to study the effects of dietary energy (DE) and crude protein(CP) and calcium (Ca) and phosphorus(P) on growth performance and serum biochemical indices of the four nutrients in 70 to 90 kg newly imported Duroc from USA. The orthogonal 4×3 factorial trial was used and 9 kind of diets were designed to determine the requirements of dietary metabolizable energy and crude protein and calcium and phosphorus of newly imported Duroc from USA. The results showed that， ①the energy, crude protein, calcium level cannot significantly（P>0.05） effect in the growth performance, the phosphorus level significant（P<0.05） effected in daily feed intake;②along the increase of the dietary energy and crude protein level, the metabolic of energy and crude protein increased, but has no significant effect（P>0.05）, along the increase of the dietary calcium and phosphorus level, the blood calcium and phosphorus increased，the phosphorus level extremely significant（P<0.01） effected in serum phosphorus. The best nutritive level in Duroc diet can be: digestive energy 14.2 MJ/kg, crude protein 18.6%, calcium 1.25%, phosphorus 0.73%, respectively.

Key words: Key words：newly imported Duroc from USA; energy; crude protein; calcium; phosphorus