An investigation into the level of professionalism among vocational subject teachers, categorized into educational and vocational expertise, revealed that vocational expertise is generally lower than educational expertise. Within educational expertise, the lowest proficiency was observed in 'utilizing digital technology in education.' In terms of vocational professionalism, the weakest area was 'effective collaboration with industry.' Upon analyzing the differences in vocational professionalism sub-areas according to teacher qualification acquisition pathways, it was found that those who graduated from teachers colleges and began their careers as vocational subject teachers generally demonstrated lower vocational expertise compared to graduates from non-teacher college education programs or graduate schools of education. The findings suggest difficulties in adequately cultivating the practical skills expected in school settings through existing teacher training programs. Consequently, there is a critical need to reform both the initial teacher training and ongoing professional development systems to ensure vocational subject teachers develop balanced expertise in both educational and vocational professionalism.