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Crop canopy sensor based estimation is a promising approach to estimate chlorophyll content of crop.CropspecTM is an active vehicle mounted crop canopy sensor, with the fixed wavebands being 735nm and 808nm.Using pulsed laser diodes as light source, the sensor is designed to irradiate the crop at an oblique view from a height of up to 4 meters in order to enable a large footprint for accurate measurements in various crops.In this paper, a set of vegetation indices (including DVI735, RVI735, NDVI735, PVI735, RDV735 and MRVI735) calculated by reflectance measured by the CropspecTM sensor were tested using correlation analysis with chlorophyll content index to explore their potentials in chlorophyll content estimation.The results showed that MRVI735 and NDVI735 are most appropriate for chlorophyll content estimation with high correlation coefficients R of-0.7842 and 0.7240 corresponding to ND8 and JNK respectively.And the correlation coefficient R of MRVI735 was higher than that of RVI735 proving that the modification was effective in improving the accuracy of RVI735 in chlorophyll content estimation.A ULR model and a MLR model were established for each cultivar.For ND8, Re2 of the ULR and MLR models were 0.6052 and 0.7774 respectively.For JNK, Re2 of the ULR and MLR models were 0.5449 and 0.5625 respectively.The results showed that MRVI735 and NDVI735 can be used in practice to estimate the chlorophyll content of different maize cultivars.The conclusions proved that CropspecTM Sensor was feasible to detect the maize chlorophyll content non-destructively and quickly and allow operators to measure the current local nitrogen supply and adapt the fertilizer application rate to meet maize requirements accurately.The study provided theoretical reference for further researches on the estimation of chlorophyll content of crop.