The purpose of this study is to investigate the effect of the spreadsheet integrated Mathematics instruction and assessment design. A project-based learning (PBL) approach was adopted for spreadsheet integrated intervention. The spreadsheet integrated performance assessment of statistic and algebra was developed as the criterion variable. Seventy-one 5th graders of Tainan and Kaohsiung were included as the sample of this PBL intervention study. One gifted and one regular class was assigned as experiment group, and another regular class was selected as control group. The difference of post-test between two regular classes is discussed by an analysis of covariance result. The preliminary result indicates that the spreadsheet integrated instruction is effective for students' mathematics learning. For the spreadsheet integrated performance assessment result, the gifted students perform better than the regular students. The assessment design needs to be revised for an easier version for further application in elementary school.