Abstract: Rice direct seeding has become an important cultivation method in the northeast saline and alkaline soil rice area in recent years.Creating new rice varieties suitable for directing seeding in salt and alkali soil is necessary for agricultural production.In this study,200 RIL population derived from XBJZ/KY131 and 142 SSR markers were used to analyze the relative seedling height,relative root number and relative root length of rice under salt and alkali stress by QTL.Under the condition of two kinds of stress,we detected 11 QTL,4 for salt resistance and 7 for alkali resistance,distribution in 1,2,3,5,12 chromosomes,LOD value range from 2.58 to 4.72,and contribution rate between 7.54%and 15.34%.By comparison,salt tolerance QTL and alkali tolerance QTL were located at the different chromosome regions,indicating that maybe there were different genetic mechanisms from rice salt tolerance and alkali tolerance at bud stage.qSRRN12 and qSRRL12,which were correlated with relative root number and relative root length,were located at the same interval under salt stress.Under alkali stress,qARSH1-1,which was related to relative seedling height,and qARRN1,which was related to relative root number,were located at the same region,qARSH1-2,which was related to relative seedling height,and qARRL1,which was related to relative root length,were located at the same region,qARRN5 and qARRL5,which were related to relative root number and relative root length,were located in adjacent regions.The correlations between QTLs located at the same or adjacent interval region and the three salt-tolerant traits,such as relative seedling height,relative root number and relative root length,were highly consistent.By comparison mapping,there were 9 QTLs in this study located in adjacent or same chromosome region with the region had been reported,which the QTLs affecting salt tolerance and alkaline tolerance related traits in different populations,but qARSH1-1 and qARRN1 detected under alkali stress had not been reported in previous studies,they may be new loci related to alkali tolerance in rice at the bud stage.