Abstract:China has large areas of Saline-alkah Soils, for which many breeding specialists including forest breeders and crop breeders have been being engaged in the breeding of saline tolerant plants. The experiment was conducted to induce the saline tolerant mutants in use of poplar callus line. In the experiment, MS was the basic culture base,2,4-D,NAA and BA were used as additives. Under a proper proportion, large numbers of embryoids or multiply shoots from some pieces of the leaves were induced. Later, these multiply shoots were induced in to the culture base with additive of NaCl. The increase gradient of NaCl. content was 1.5-3%. Totally, the subculture was continued for eight times. For each time, it was 30 days. Complete plants were formed from multiply shoots growing in the MS with 12.5% NaCl content.In the process of physiological inducement of saline tolerant mutants, explants demonstrated different degrees of tolerance as in the order of yellow leaf, indifferentiation of root organs, inhibition of root system development, normal growth of root system, and complete plant with good growth. The mutants not only increase the saline tolerance, but also produce an obvious variation of morphology and isoenzyme spectrum of peroxidase enzyme.Different poplar species showed different reactionsin the inducement process. Saline tolerant (content 12.5%) mutants could be induced for Populus nigra, P. × beijingenses Cl ‘8000‘. For P. diltoides Cl ‘lux‘ and P. catheyana the root organs only could not differentiate. For P. maximowiczii, P. ×uramencana C1 ‘cima‘ and P. Popularis C1 ‘36‘ explants died as the NaCl content increased to 9%.