Abstract: An orthogonal design was adopted in this trail to study the effects of nitrogen, phosphorus, potassium on the movphological and physiological characters of 1-year-old container slash pine (Pinue elliottii) seedlings, and the nutritional diagnosis was made in two ways. The results show that. (1) The different propertions of nitrogen, phosphorus and potassium have great influen-ces on both of the characters, and there are obvious variations between the treatments. (2) The reasonal fertilization amounts for individual seedling analysed in quadraic function are as follows: nitrogen 0.161-0.189; phosphorus 0.315?.358; potassium 0.120-0.240. (3) The different proportions of nutritional elements in leaf, shoot and root. Its reasonal concentrations in leaf are nitrogen 1.26-1.83%; Phosphorus 0.18-0.28%; potassium 0.894.43%. (4) The nutritional state could be evaluated by both morphological, physiological characters diagnosis and DRIS, and the feitilization requirement of seedling could be determined accurately.