| This paper studied the change of physiology of burley tobacco during air-curing and the influence of microwave treatments and different harvesting methods on quality of burley tobacco. The research results as follows:1.The water decreased slowly at former stage of burley tobacco air-curing (about 84 hour), then decreased intensely, at the same time, the content of malondialdehyde(MDA) increased, and the integration of cell was destroyed, the lipid peroxidation was aggravated, so the formal action of live vanished, and the metabolism of matter tend to corruption. The dynamic change of water was significantly negative correlation with MDA(r=-0.821*)2.The content of O2- and H2O2 both increased intensely between 0～84h with the progress of air-curing, then the change tended to stability; The active of ascorbic acid oxidase(AAO) increased during air-curing and reached acme at 84h, then changed little, but the content of ascorbic acid(AsA) decreased all the time. There was significantly negative correlation between water and AAO (r=-0.747*), it showed that the activity of AAO increased when water decreased at limited range; the activity of glutathione reductase(GR) decreased intensely between 0～84h, then the activity of enzyme tended to stability with the loss of water; to the contrary, the content of GSH increased slowly all the time during air-curing and reached acme at 84h, then stabled level off. There was significantly negative correlation between the active of GR and the content of GSH(-0.956**).3.The content of chlorophyll decreased intensely between 0～84h during burley tobacco air-curing, but the content of carotenoid decreased slowly; 84h later, the content of chlorophyll and carotenoid were stable. It showed that the former 84h was a key stage for the decomposition of pigment. There was significantly negative correlation between pigment and water(rChl=0.725*, rCar=0.798*). 4.In the course of air-curing, it were significantly positive correlation between water and GR, chlorophyll and carotenoid(rGR=0.818*, rChl=0.825*, rCar=0.811*), but it were significantly negative correlation between water and MDA, O2-, H2O2, GSH(rMDA=-0.949**, r O2-=-0.850*, r H2O2=-0.866*, rGSH=-0.807*). The further correlative analysis showed that it was significantly negative correlation between the active oxygen and the activity of GR(r=-0.985**); the correlation of O2- and H2O2, MDA both reached significant level(rH2O2=0.955**, rMDA=0.756*). It showed that the action of lipid peroxidation aggravated gradually during air-curing, and the activity of GR lowed significantly, the content of AsA lowered, so the action of cleanup to active oxygen vanished gradually, and caused continuous accumulation of O2-, H2O2 and MDA.5.The water dissipated rapidly after microwave radiation at the latter stage of yellowing, it was most apparent by treating 90s(B3), then was 60s(B2) and 30s (B1), but the velocity of water dissipating of them were all much higher than which air-cured in normal(B); the lipid peroxidation action of leaves was aggravated treated by microwaves, the content of MDA of every treatments were all higher than B, the content of MDA was most high in B3, that was most low in B2; the content of chlorophyll decreased intensely at the stage of yellowing, then decreased gradually, but the content of carotenoid decreased slowly all the time. After treated by microwave, the content of chlorophyll and carotenoid were both higher than B, the change rule of chlorophyll and carotenoid were similar, and the rule of them was B3>B1>B2>B.6.The content of starch and total sugar decomposed massively at the stage of yellowing, the interior intense consume of breath at the former stage of air-curing caused the low content of total sugar. The content of starch lowered by microwave treatment, the change rule of them was B>B3>B1>B2,but the total sugar was contrary. It showed that the decompose of starch could be aggravated with microwave radiation, and increased the content of total sugar at a certain extent；the content of total nitr...
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