The invention discloses a culture medium for delaying the growth of potato tissue cultured seedlings. Every 1L of the culture medium comprises the following components: 627mg-693mg of ammonium nitrate (NH4NO3), 722mg-798mg of potassium nitrate (KNO3), 168mg-184mg of calcium chloride (CaCl2.2H2O), 160mg-176mg of magnesium sulfate (MgSO4.7H2O), 65mg-71mg of monopotassium phosphate (KH2PO4), 0.315mg-0.348mg of potassium iodide (KI), 2.36mg-2.60mg of boric acid (H3BO3), 6.43mg-7.09mg of manganese sulfate (MnSO4.4H2O), 3.27mg-3.61mg of zinc sulfate (ZnSO4.7H2O), 0.095mg-0.105mg of sodium molybdate (Na2MoO4.2H2O), 0.009mg-0.011mg of copper sulfate (CuSO4.5H2O), 0.009mg-0.011mg of cobalt chloride (CoCl2.6H2O), 28.5mg-31.5mg of ferric sodium edelate (FeNa2EDTA.H2O), 38mg-42mg of inositol (C6H12O6), 0.19mg-0.21mg of nicotinic acid (C6H5NO2), 0.19mg-0.21mg of pyridoxine hydrochloride (C8H11NO3.HCl), 0.038mg-0.042mg of thiamine hydrochloride (C12H17ClN4OS.HCl), 7600mg-8400mg of cane sugar (C12H22O11), 7600mg-8400mg of mannitol, 6650mg-7350mg of agar and the balance of water. By adopting the culture medium disclosed by the invention, the potato tissue cultured seedlings grow slowly and need 140-150 days to grow to a height of 8cm since the inoculation date, thus the preservation time of the potato seedlings is remarkably prolonged.