The purpose of this study is to determine effectiveness Learning Group Investigation Model Flashcard Media Helped Science Learning Results Material Resources Energy Student Class III SDN Sawah Besar 01 Semarang. This type of research is quantitative research in the form of True Experiment Design. The population in this study is the overall grade 3 students SDN Sawah Besar 01 Semarang. The samples taken are 40 students from each class. Class Control using Simple Random Sampling technique. The research design used is Pretest-Posttest Control Group Design. This research data is obtained through research instrument of pretest, posttest, documentation, test, interview. Based on the analysis result of learning result of control class and experiment class by using result of t test calculation obtained tct = 6,026. From the t distribution list with dk = 40 + 40 - 2 = 78 we get 1.991. Because tcount 6.026> 1,991 ttable then Ho is rejected, so it can be concluded that the average learning result of experimental class (82,1) is bigger than control class (70,6). Based on the results of classical completion of learning in the experimental class after being given treatment using learning model group investigation assisted flashcard media obtained 95% learning mastery score, compared to control class only get 60%. So it can be concluded that the model of study group investigation assisted flashcard media on the learning outcome of science class energy resources class III SDN Sawah Besar 01 Semarang effective.