The purpose of this research is to improve students' understanding and the ability to perform scientific work through creative problem-solving learning with the open-ended experiment approach to the separation of mixtures material using online learning. The study used a quasi-experimental method with the nonequivalent pretest-posttest control group research design. This study involved 72 students divided into two classes, 36 students in the control class and 36 students in the experimental class. Indicators of scientific work are formulating problems, describing problems, designing investigations, conducting experiments, processing data, and concluding. The results of the study showed an increase in the students' ability to perform scientific work, obtaining N-Gain of 71% (experimental class) and 48% (control class), as well as the value of t[subscript count] = 8.807 indicating t[subscript count] > t[subscript table]. The percentage of students' scientific work in the experimental class was in a very good category with 72%, while the control class was 53%. Thus, creative problem-solving learning through the open-ended experiment can improve students' understanding and scientific work.