The effects of CaCl² of 0,5,10,15 and 20 mmol·L^-1 in the culture medium on the carbohydrate metabolism and enzymes of potato variety of ‘Kexin No.1’ were investigated under 0,25,50 and 75 mmol·L^-1 NaCl stress.The results showed that:(1)With the increase of NaCl stress concentration,the contents of starch,sucrose,glucose,fructose and total soluble sugar in leaf of potato virus-free seedlings decreased continually.Sucrose synthetase(SS) and sucrose phosphate synthase(SPS) activities were significantly reduced.The activities of neutral invertase(NI) and acid invertase(AI) in leaf elevated in the range of 0～50 mmol·L^-1,and then declined.(2)Under NaCl stress,adding proper amount of CaCl² significantly increased starch,sucrose,glucose and total soluble sugar contents,significantly reduced the activities of NI and AI,could effectively alleviated the inhibitory effect of the salt stress on SS and SPS.(3)There were a negative correlation between sucrose content and AI activity,there were a significant negative correlation between sucrose content and NI activity,and there were significant positive correlation between sucrose content and activities of SPS and SS.These results indicated that exogenous calcium could regulate enzyme activity change,ameliorate the potato virus-free seedlings direction of carbohydrate metabolism under salt stress,enhance plant carbon synthesis and osmotic adjustment,and reduce salt damage.