The purpose of this research is to examine the status of the operation and implementation of Integrated Science and Science Laboratory Experiments courses, their effectiveness and adequacy as common courses in the 2015 revised curriculum, as well as ways to maintain these subjects as common subjects for the next curriculum revision. A survey with 157 general high schools and focus-group interviews with 10 science teachers were conducted to investigate the status of these two subjects. According to the results, most of the Integrated Sciences courses were implemented in 6-8 units over two semesters, and 2 units over two semesters for Science Laboratory Experiments courses, which is determined by the number of teachers for each subjects and their majors. Regarding appropriateness as a common subject, 66.9% of teachers for Integrated Science and 57.9% for Science Laboratory Experiments said it was appropriate as a common subject. For the need to designate common subjects in the next curriculum, 76.5% of teachers for Integrated Science and 52.9% for Science Laboratory Experiments said these two subjects are necessary to be designated as common subjects. Based on the research results, the necessity to maintain Integrated Science and Science Laboratory Experiments as common compulsory subjects for all students in the 2022 revised curriculum, strengthening the nature of Integrated Science focusing on competency education, career guiding through Integrated Science classes, realizing science literacy education through standards-based assessment, and widening of teacher certification areas were suggested.