The aim of this study was to analyze dry matter accumulation and phosphorus（P）efficiency in six types of Pefficiency genotypes cotton at different P application level in different growth periods by hydroponics technique. Results showed that the cotton biomass of high Pefficiency genotypes was higher than that of low Pefficiency genotypes at both low and high P levels. However，the P content of low Pefficiency genotypes was significantly higher than that of high Pefficiency genotypes. In the four growing stages，P uptake efficiencies at high P level were higher than those at low P level. P use efficiency was significantly higher in low P condition than that in high P condition. Moreover，P uptake efficiency and P use efficiency of high efficiency genotypes were higher than that of low efficiency genotypes. The average P uptake efficiency of Xinluzao 19 was the highest in the six genotypes studied，and the average values were 14.62 mg/plant and 137.48 mg/plant at low and high P levels，respectively. The average P use efficiency of Zhongmian 42 was the highest，and their values were 590.71 g/g and 182.27 g/g at low and high P levels，respectively.