Rapid real-time monitoring of wheat nitrogen (N) status is crucial for precision N management during wheat growth. In
this study, Multi Lookup Table (Multi-LUT) approach based on the N-PROSAIL model parameters setting at different
growth stages was constructed to estimating canopy N density (CND) in winter wheat. The results showed that the
estimated CND was in line with with measured CND, with the determination coefficient (R<sup>2</sup>) and the corresponding root
mean square error (RMSE) values of 0.80 and 1.16 g m<sup>-2</sup>, respectively. Time-consuming of one sample estimation was
only 6 ms under the test machine with CPU configuration of Intel(R) Core(TM) i5-2430 @2.40GHz quad-core. These
results confirmed the potential of using Multi-LUT approach for CND retrieval in winter wheat at different growth
stages and under variables climatic conditions.