Mapping of QTLs for heat tolerance of wheat(Triticum aestivum) in response to high temperature Abstract In cereals heat stress during seed formation is critical factor in lowering yield. This study was conducted to identify and map QTLs for heat tolerance in wheat in response to two heat treatments (short term- and long term-) during seed formation using recombinant inbred lines derived from a cross of '7C'(heat resistant) and 'SERI M 82'(heat susceptible). Yield components such kernel number, kernel weight, and grain filling duration were used as an indicator of heat susceptibility. The phenotypic variation of yield components were normally distributed, suggesting that the yield components have quantitative heritability over high temperature. Transgressive segregation compared to parents was also observed, suggesting that genetic variation from an optimal recombination of favorable loci from both occurred in the progeny population. 113 SSRs markers among 320 SSRs markers polymorphic between the two parents '7C ' and 'SERI M 82' with a linkage coverage of 2609cM and average interval map distance of 25 cM throughout the whole genome. QTLs for heat tolerance and their genetic effects were analyzed by association of % reduction of each phenotypic trait of yield components with polymorphism in the 62 RILs. 11 QTLs and 22QTLs for heat tolerance under short- term and long- term heat stress, respectively were detected from each of the phenotypic trait of yield component, showing phenotypic variation of 93 % and 86%, respectively.