The purpose of this research to determine whether cooperative learning model through the use of snowball throwing prized chart is more effective than conventional learning model to mathematics learning outcomes seventh grade students of SMP Negeri 11 Yogyakarta. The population consisted of 137 students were divided into four classes. The sample selection is in this study using cluster random sampling technique. Data analysis techniques in this study using t-test, and than compares tobservated with ttable, with df = n1 + n2 -2, and α = 5%. If tobservated  ttable , then Ho is refused, meaning that the average score of the achievement of the experimental classes are better than the average score of the achievement of the control class. The research is found that the average achievement scores (gain) = 4.64 and the experimental class average achievement scores (gain) control class = 3.48. Obtained with  and  tobservated = 2,214 > ttable = 1,645 then Ho is refused, it means the average achievement scores (gain) achievement test on the subject of rectangular and square in the experimental classes are better than the control class. So it can be concluded that the cooperative learning model through the use of snowball throwing prized chart is more effective than conventional learning model to mathematics learning outcomes seventh grade students of SMP Negeri 11 Yogyakarta.