The purpose of this study was to understand the teaching effects according to the cognitive levels after conducting inquiry activities using science notebooks in the open inquiry activities of the elementary science class. The results of this study were as follow. first, students having the open inquiry activities using science notebooks showed improvement in scientific inquiry abilities in both groups with the low and high cognitive level. Second, regarding the changes of scientific attitudes, both groups with the low and high cognitive level exhibited improvement. According to the result of analyzing interaction between the cognitive level and class treatment on the effects for scientific inquiry abilities and scientific attitudes, there was no difference by the cognitive level. And the use of science notebooks in open inquiry activities had effects on improving scientific inquiry abilities and scientific attitudes regardless of the cognitive level.