Abstract: To reveal the rules of nitrogen， phosphorus and potassium absorption and distribution and explore the mechanism of bulb development， the dry weight and the content of nitrogen， phosphorus and potassium in tulip was investigated during its growth periods under cultivation conditions. According to the growth characteristics， the whole growth and development process of tulip was divided into four phases. StageⅠis the main growing period for roots with lower nitrogen， phosphorus and potassium nutrient absorption amount. StageⅡ is the main growing period for stem and leaves with higher absorption amount of nitrogen， phosphorus and potassium nutrient， especially nitrogen. Stage Ⅲ is flowering period and the uptake percentage of potassium reach the peak of the whole growth period. In the first three stages， all of the nitrogen， phosphorus and potassium nutrient were mainly from mother bulb. Stage Ⅳ is the main period for the daughter bulb growing and requiring more nutrients. In conclusion， we recommend that sufficient nitrogen should been provided around the whole growth and development process， and additional potassium should been provided in later floral period of stage Ⅱ， so as to ensure the flower quality and the growth of daughter bulbs of tulip.

Key words: tulip, nitrogen, phosphorus, potassium, absorption and distribution, fertilization