Abstract: Electric conductivities in detached-leaf of eleven cultigens of Ilex from domestic and abroad were under simulated frozen treatment. Lethal temperature 50 (LT50 ) was calculated with logistic formula and the results revealed that the frozen resistance from strong to weak were Ilex crenata var. convexa, I. viridis, I. ×altaclerensis ‘Lawsoniana’, I. cornuta, I. chinensis, I. cornuta var. fortunei, I. ×altaclerensis ‘Golden Van Tol’, I. pubescens, I. aferox ‘Avgentea’, I. m icrococca, I. crenata ‘Golden Gem’. Nine cultigenswere selected based on the above results and their leaves were detached and treated at different low
temperature to measure the contents of sucrose and p roline. The results indicated that with temperature decreasing, the contents of soluble sucrose and proline increased, and the contents were positively related to the
frozen resistance in some cultigens. The research results demonstrated important indexes to predict the frozen resistance of other new introduced plants.

Key words: Ilex L., Frozen resistance, Electric conductivity, Soluble sucrose, Proline