The purpose of this study is to diagnose the current states and the problems of student assessment of Elementary School Mathematics. For that purpose, this study conducted a survey and had the individual interviews. The surrey items consisted of the six main parts: questions about the development of assessment tools, the method to assess, the grading, the special supplementary courses, the opening of learning effect, and the follow-up guidances. The results of this study are as the follow First, elementary teachers depended heavily on internet sites for developing assessment problems. Second, elementary teachers made use of a performance assessment, a unit assessment, and a term examination at ordinary times. Third, unit assessment was largely referred for grading by elementary teachers. Fourth, in selecting the students for the special supplementary courses, both criterion-referenced assessment and norm-referenced assessment were considered. After finishing the special supplementary courses, additional tests were usually taken. Fifth, elementary teachers took a negative attitude in opening of learning effect. specialty opening of test paper to parents of students was done under 30%. Sixth, fellow-up guidances were the most through the classroom guidances. but consulting with parents of students was not frequently conducted by teachers.