The purpose of this study is to research about the effects on improvement academic achievement of students based on the core learning standards of science.The researcher selected experimenter and started this study as a graduate student who is majoring in science education, experimenter chose to study 48 Sixth graders in elementary schools in B city for research group(24 students), Comparison group(24 students). The study was conducted from March to the end of July 2014. The teacher who is doing activity of professor in research group and the comparison group is science education specialist. Researcher and experimenter frequently exchange their opinions for control variables of teacher.The results are as follows. First, based on unit time strategies based on core achievement standards classes are effective in improving students' academic achievement. Elementary school teacher has difficulty in teaching for all subjects based on unit time strategies.Second, based on unit time strategies based on core achievement standards classes showed high level of satisfaction in perception of students.Thus it can be seen that teaching strategies of unit time based on the core achievement standards is effective to academic achievement improvement.The proposal for further study based on the results is as follows. First, research is needed to study the teaching methods that have practical and theoretical study time and lesson application opportunity for teaching strategies of curriculum unit time.Second, experimental studies that using strategies of unit time based on the core achievement standards are needed about learning method that can be applied in a variety of subjects.