The objective of the study is to investigate the effect of applying a scientific approach to improve recommended competencies of English junior high school teachers. A quasi-experimental design was employed with the use of convenience sampling techniques to select research subjects for control and experimental groups. The 30 items test was developed and used in pre-test and post-test for collecting data. The data were analyzed using t-test analysis to measure mean differences of the data sets from control and experimental groups. The result of data analysis indicates that the mean score of the experimental group, 77.19 is greater than the control group 61.15. This result shows the use of the scientific approach to teach research subjects in an experimental group has an effect in improving their competence on the recommended competencies mandated by the Law and regulations.