研究目的：不同的施氮量和不同时期下，分析施氮水平对大豆若干生理指标的影响，为今后研究大豆的各项生理指标提供科学依据；方法：通过光谱仪和SPAD-502叶绿素计等仪器，测定V3、V4、V5、R1、R2、R3、R4、R5、R6、R7和R8时期大豆叶片光谱、叶绿素、叶面积和氮含量，在不同施氮水平下，研究大豆各生理指标变化规律；结果表明：不同的施氮水平对大豆叶面积、氮素和叶干重的影响趋势一致，即N2>N1>N3>N0，其差异都达到了极显著水平，SPAD值的分析结果表现为N3>N2>N1>N0；结论：在不同生育期内各生理指标的不同施氮水平间差异显著或极显著。

【OBJECTIVE】≈Different nitrogen application and different times, the analysis of nitrogen levels on some physiological indices of soybean, soybean for future research to provide scientific evidence of the physiological indicators ; 【METHOD】≈In order to research orderliness of physiological indexes of soybean in different nitrogen treatment, we maked use of NIRS and SPAD-502 instrument and so on to mensurate leaf spectra, chlorophyll, leaf area and nitrogen content of soybean in different growth period ; 【RESULTS】≈The results showed that influence on the trend line of leaf area, nitrogen content and leaf dry matter accumulation of soybean in different nitrogen treatment, they were N2>N1>N3>N0, and existed highly significant difference, it was N3>N2>N1>N0 in SPAD;【CONCLUSION】≈ Growth period in the different indicators of various physiological differences between different N levels were significantly or very significantly.