Abstrack: The research aims to increase student learning achievement on the subject structure of atoms and the periodic system of elements in class XI science SMAN 1 Pasir Penyu. This research was of experiment research with pretest-posttest design. The samples of this research were the XI science 3 as the experimental group and XI science 1 class as the control group. In experimental group was applied cooperative learning snowball throwing model, while the control class was not. Data analysis technique used is the t-test. Based on analysis data tcount>ttable is 2,7 > 1,67, means that the application of model cooperative learning snowball throwing can improve student achievement on the subject structure of atoms and the periodic system of elements in class XI science SMAN 1 Pasir Penyu by category increase achievement (N-Gain) high at 0.73.Keywords: Learning Achievement, Cooperative snowball throwing, Atomic Structure and Element of the Periodic System.