So far, all comparisons among different hexaploid oat populations were based on maps built with different methods and even different softwares. Integrated maps built by different hexaploid oat populations have not been reported. In this study, the maps of the two hexaploid oat populations developed from crosses Kanota by Ogle (K x O) and Ogle by TAM O-301 (O x T) were generated using the mapping program, JoinMap 3.0, and using the same mapping methods. Some obvious differences between the maps of this study and the original maps made by Wight et al. and Portyanko et al. were discussed. Evidence that Group 5 should be joined with Group 30, Group 6 should be joined with Group 9 in the original K x O map, and Group 4 should be joined with Group 7 in the original O x T map was proposed. The correction of joining Group 19 and Group 27 and joining Group 7, Group 10, and Group 28 during building the original K x O map was confirmed. The integrity of Group 39 in the original K x O map and Group 1 and 28 in the original O x T map was brought into question. Nineteen pairs of groups between the K x O map and O x T map shared three or more than three common markers. Some groups of one population shared three or more than three common markers with two or more than two groups of the other population. These common markers had the same order in just four pairs of groups, KO 412̲ and OT 4(2), KO 412̲ and OT 29, KO 5-30 and OT 8(1), and KO 14 and OT 34. In just two pairs of linkage groups, KO 412̲ and OT 29, KO 14 and OT 34, which we called consensus groups, was the order the same and were recombination frequencies similar among these common markers. Two integrated maps were obtained by merging these consensus groups.