Thermo-tolerance of 95 accessions of javanica rice, which originated from different countries and regions, was determined by high temperature stress in phytron and interval sowing in field. According to the comprehensive seed set, the 95 accessions of javanica rice were classified into 3 groups by thermo-tolerance based on clustering analysis. In consideration of comprehensive seed set and seed set of interval sowing in field, the variety of IRAT109 (IRRI accession number 38563), 260 (IRRI accession number 14888) and L 4-34 (IRRI accession number 13403) were of thermo-tolerance, which can be used for breeding new thermo-tolerant rice and genetic research of high temperature stress.