The purpose of the study was to define five science core competencies introduced in the 2015 revised science curriculum with each component and practical indicators into the frame. Science teachers on site could use it in teaching and developing science program to equip students with the competencies to creatively solve problems which is the aim of science education in the 21st century. To develop this frame, we contacted 10 experienced science educators and collected the data through a questionnaire. We coded all responses and categorized into the components and practical indicators of each competency which were all compared with those from well-known theories in order to validate. We then contacted other 35 science educators again to construct the validity to fill out the survey of Likert scale. The finalized science core competency included 19 components in total with practical indicators that can be observable and measurable in the classroom. This frame was used to see how it fits into a STEAM program. The finding was that two different topics of the STEAM program displayed the different description of science core competency usage, which could be used as the prescription of the competency as to whether or not it is more promoted in science class.