The 21st century demands the students to develop thinking skills, one of which is the ability to think creatively. Study results from the PISA year 2015 show that scientific thinking skills students are still low. One approach to learning that can be used to train the ability of creative thinking is learning approach to STS. It is said to be effective when supported with learning materials be worksheet. The purpose of this research is to know the effectiveness of sains-based STS is worksheet to train creative thinking skills of students of Junior High School. The research design used was pre-experimental in form of pre-test post-test non-equivalent design. Based on the results of test effectiveness, then it is known that the N- Gain on each of the meetings has increased with the average value of a meeting 1 of 0.5, 0.6 and 2 meetings of the meeting 3 of 0.6. Creative thinking skills of students tend to experience increased every charge indicators will namely indicators think smoothly on the 1st and 2nd meetings of the 3rd meeting of 0.4 and 0.5. Indicator flexible thinking in the 1st and 2nd meetings of the 3rd meeting of 0.4 and 0.6. The indicator think original confluence of 0.3 and 1 meetings 2 and 3 amounted to 0.5. The indicator think detailing the meeting 1 of 0.3 and meetings 2 and 3 amounted to 0.4. Based on the research that has been done, it can be concluded that-based STS is worksheet as having been effective in training the creative thinking skills of students of Junior High School