Much researches of Near-infrared spectroscopy modeling methods that are utilized to analyze the trace amount components,especially indirect modeling on complex system,have gained widely attraction in recent years.Amino acids in plants are essential nutrients of maintaining growth and ensuring health.As the important participants in various biochemical reactions in plants,nondestructive detection of free amino acids will provide meaningful observation on physiological changing in different steps of plant growth.In this research,two hundred and twenty-two samples were measured to obtain the concentration of free L-Asparagine in plant by amino acid analyzer.NIR spectra were also collected for conducting chemometrics modeling.Different spectral pretreatments and variables selecting methods were employed to optimize the NIR models.Independent validation set as well as unknown samples from different years were successfully predicted by using the slope intercept correction.Results in this study demonstrated that fast analysis of free L-Asparagine can be established by NIR modeling approach.