Abstract: Plantlets in vitro of three clones，which were previously selected out for their high salt （NaCl）tolerance，were investigated under various levels（0，10，20 and 30 mmol • L-1）of NaHCO3 and NaCl for their growth parameters，shoot length，root length，shoot fresh weight，root fresh weight，shoot dry weight and root dry weight. With increase in the level of NaCl，values of the six growth parameters for the three diploid potatoes were increased，and then deceased. However for NaHCO3，they were kept on to be deceased. The values of growth parameters under NaHCO3 stress were dropped more compared with NaCl. For the same clone，NaHCO3 would do more harm than NaCl under the same concentration.

Key words: potato, diploid, NaHCO₃, growth