LCO and TH17 paly an important role under abiotic stress.In order to explore the effects of LCO and TH17 on the yield and protective enzyme activities of oat under drought stress,we conducted this experiment by foliar-spraying the oat (Bayou 3) with 0.01 μmol/L concentrations of LCO and TH17 in growth cabinet with potting,to compare several changes of oat yield,osmotic regulation substances and protective enzyme activities.The results showed that:(1)The growth and development of oat were promoted under the normal water condition spraying LCO and TH17 and the yield of oats increased;under drought stress,LCO and TH17 could reduce the reduction of plant height,spike length,spike grain number,biological yield,grain weight per plant and the accumulation rate of dry materials of oats.In the seedling stage,spraying LCO and TH17 in the increasing rate of seedling stage single spike grain weight increased by 61.25% and 65.00% than that of SS_CK,respectively.(2)The LCO and TH17 could increase free proline content in elongation stage under drought stress,and increased by 27.19% and 41.00% than that of SS_CK,respectively.The highest increase rate of soluble sugar content was in the heading stage,it increased by 61.43% and 112.54% than that of SS_CK,respectively.The highest increase rate of soluble protein content was in seedling stage,and increased by 9.58% and 13.80% than that of SS_CK,respectively.(3)Under drought stress,the SOD and POD activities increased after spaying LCO and TH17 in heading stage and the CAT activity in the elongation stage.(4)Under drought stress,the LCO and TH17 could reduce the amplitude of the highest relative conductivity and MDA content in seedling stage,decreaesd by 17.61%,36.67%,43.43%,30.28% than that of SS_CK,respectively.In summary,the effects of spraying LCO and TH17 in seedling stage was the largest;the LCO and TH17 can increase contents of osmotic adjustment substances and activities of protective enzymes in oat under drought stress.