Abstract: To explain the effect of different freezing injury prevention measures on Korla Fragrant pear trunk cambium temperature changes and alternately freezing during over-wintering period, adopting different color smearing and different material covering method, detect trunk cambium temperature changes using thermo-couple probe. Results showed that the different treatment with color smearing and covering has an obvious effect on trunk cambium changes and alternately freezing, after color smearing treatment, the order of the alternately freezing extent is scraping bark>black>CK>white; the alternately freezing extent sequence of different material covering treatment is CK>hemp rope>reflecting film>wool mat>rice straw; the diurnal cambium temperature changes of trunk covering treatment is obviously smaller than trunk different color treatment, the diurnal cambium temperature changes of whitening averagely 3-5℃higher than the diurnal cambium temperature changes of wool mat and rice straw covering treatment. Among the different freezing injury prevention measures whitening , wool mat and rice straw covering treatment has best efficiency.