Under hydroponic conditions，Chang72 were used to study the effect of different PEG6000 concentrations（10 %,12.5%,15%,17.5%,20%,22.5%,25%）and different concentrations (5,10,15,20,25,30 mg / L) plant growth regulator 2(3,4dichlorophenoxy1)triethylamino（DCPTA）under 15.0% PEG6000 simulated drought stress on maize seedling growth and antioxidant enzyme systems. The results showed that, biomass index(dry and fresh weight of shoot and root), leaf relative water content(RWC) and SPAD value decreased after the PEG6000 treatment, antioxidant enzyme (SOD, POD, CAT) activities ,malondialdehyde (MDA) content and osmotic adjustment substance (soluble protein, proline) accumulation increased，when PEG6000 concentration reached 15%. The indices significantly different from control; The treatment by addition of DCPTA to the hydroponic solution induced an increase in drought tolerance during subsequent exposure to 15% PEG6000 water stress. This was evidenced by the indices (biomass, RWC, SPAD, antioxidant enzyme activities, MDA content and osmotic adjustment substances) of maize seedling. We can concluded preliminarily that the appropriate PEG6000 concentration for the identification of maize drought tolerance in seedling stage was 15%; DCPTA could enhance drought tolerance of maize seedling by modulating growth, increasing osmotic adjustment substance accumulation and antioxidant enzyme activities. The appropriate concentration was 15 and 20mg/L.