Abstract: To find out the hyperspectral characteristics of field leaves of flue-cured tobacco with different maturity,the differences of spectral parameters,including hyperspectral reflectance,variables about position, area and vegetation,between leaves of different maturity were analyzed by taking upper leaves as objects. The results showed:1) Within the range of visible bands (400-680 nm),the reflectance of leaves was lower than 35%,and it increased gradually with the increase of maturity,especially in the range of 550-680 nm,in which the leaves of different maturity could be well discriminated from each other;while in the range of infra-red bands,the reflectance was about 60% and it decreased with the increase of maturity. 2) Along with the increase of maturity,the reflectance of green peak (Rg) and red valley (Rr) increased,the locations of green-peak (λg) and red-valley (λv) tended to lag behind,while red-edge (λr) advanced gradually,the ratio of red-edge area to blue-edge area (SDr/SDb) and the normalized ratio of SDr to SDb(SDr-SDb)/(SDr+SDb) significantly reduced,and the Rg/Rr,the normalized ratio of Rg to Rr(Rg-Rr)/(Rg+Rr) tended to decrease. Some of the spectral parameters varied regularly with the increase of maturity,which provided a base of data and theory for developing a tool to discriminate the maturity of leaves in field with spectral parameters.