A work machine comprising: a travelable track structure ; a swing structure provided swingably on an upper side of the track structure ; a work device coupled to a front side of the swing structure ; a blade provided on a front side of the track structure such that the blade can be raised and lowered; and a lift cylinder that raises and lowers the blade , characterized in that the work machine includes a swing-structure-position acquiring device that acquires a horizontal coordinate and an orientation of the swing structure , a swing sensor that senses a swing of the swing structure , a travel sensor that senses travelling of the track structure , and a controller (35; 35A; 35B; 35C; 35D) that is configured to compute an orientation of the track structure , and a horizontal coordinate of the blade , and the controller (35; 35A; 35B; 35C; 35D) is configured to compute the orientation of the track structure by using a locus of the horizontal coordinate of the swing structure , the horizontal coordinate being acquired by the swing-structure-position acquiring device , in a case where a swing of the swing structure is not sensed, and travelling of the track structure is sensed, and is configured to compute the horizontal coordinate of the blade on a basis of the computed orientation of the track structure , and the horizontal coordinate and the orientation of the swing structure acquired by the swing-structure-position acquiring device . a travelable track structure ; a swing structure provided swingably on an upper side of the track structure ; a work device coupled to a front side of the swing structure ; a blade provided on a front side of the track structure such that the blade can be raised and lowered; and a lift cylinder that raises and lowers the blade , characterized in that the work machine includes a swing-structure-position acquiring device that acquires a horizontal coordinate and an orientation of the swing structure , a swing sensor that senses a swing of the swing structure , a travel sensor that senses travelling of the track structure , and a controller (35; 35A; 35B; 35C; 35D) that is configured to compute an orientation of the track structure , and a horizontal coordinate of the blade , and a swing-structure-position acquiring device that acquires a horizontal coordinate and an orientation of the swing structure , a swing sensor that senses a swing of the swing structure , a travel sensor that senses travelling of the track structure , and a controller (35; 35A; 35B; 35C; 35D) that is configured to compute an orientation of the track structure , and a horizontal coordinate of the blade , and the controller (35; 35A; 35B; 35C; 35D) is configured to compute the orientation of the track structure by using a locus of the horizontal coordinate of the swing structure , the horizontal coordinate being acquired by the swing-structure-position acquiring device , in a case where a swing of the swing structure is not sensed, and travelling of the track structure is sensed, and is configured to compute the horizontal coordinate of the blade on a basis of the computed orientation of the track structure , and the horizontal coordinate and the orientation of the swing structure acquired by the swing-structure-position acquiring device . <EOS>