Abstract: We analysis machine-transplanted seedling quality and nutrient absorption under different fertilizer treatment, to clarify their nutritious need for nitrogen, phosphorus and potassium, to provide basis for strong seedling and high yield. We selected a seedling fertilizer recommended by Jiangsu Province Agricultural Technology Extension Station, the ‘Seedling Partner’, as nutrient gradient regulator, observe into seedling physiological characters under various treatments: No Fertilizer (NF), Low Fertilizer (LF), Moderate Fertilizer (MF), Slightly Over Fertilizer (SOF) and Over Fertilizer (OF). The results show that: 1. Fertilization directly causes soil nutrients increase. MF processing is beneficial to strong seedling, can reduce loss of nutrient and improve nutrient utilization; 2. Seeding has higher demand for nitrogen, phosphorus than potassium. OF processing is harm to strong seedling because of excessive nutrient accumulation; 3. In Transplanting Stage, root length, root diameter, root surface area, root volume of LF processing is respectively 25.59%, 19.31 %, 44.44%, 27.13% more than those of OF processing. Generally, MF treatment can produce suitable root packing force, which is more conducive to machinery transplanting; 4. GS, GOGAT, GOT, GPT activity of aboveground is more active than those of root. With addition of fertilizer, GS, GOGAT, GOT activity of aboveground increase but GS, GOGAT, GPT activity of root firstly increase then decrease. Peaks appeared in LF and MF processing. An appropriate amount of fertilizer is helpful to ammonia conversion and nitrogen metabolism, can produce quality seedling for machinery transplanting, to achieve stable and high yield after transplanted into big field.