Objectives : The aim of the study is to investigate job performance expectations according to duration of work and to specify the clinical practice of dental hygienists by career expectations. Methods : The subjects were 310 dental hygienists in Seoul and Incheon. They completed the self-reported questionnaires and 304 data were analyzed except incomplete 6 answers. Results : The tasks performed by dental hygienists were as follows ; SS crown restoration in pediatric dentistry accounted for 25.1%, orthodontics (42.1 %), plaque removal (71.4 %), temporary fillings (60.5%), and impression taking of abutments and bite registration (58.9%). In order to be a skillful dental hygienists, it took two to three years of clinical filed work. Conclusions : On the job training (OJT) is the most important in dental hygiene curricula. So it is necessary to develop the OJT performance skill.