The background of this research is the low learning achievement and student interaction while having a discussion in grade V of SD Negeri 3 Tambaksogra. This study aims to discover the implementation of cooperative learning model namelyTeam Assisted Individualization (TAI) in increasing student learning interaction and achievement. The subjects of this research were 24 fifth grade students. This was a classroom action research conducted in 2 cycles. Every cycle consisted of 2 meetings. The steps taken in each cycle were planning, implementing, observing, and reflecting. An evaluation was held at the end of each cycle by working on an evaluation question sheet. The result of learning interaction increased from 50% in cycle 1 to 70% in cycle II. The increase in learning achievement can be seen from the results of the students learning evaluation in each meeting. Based on the result of the evaluation test of Natural Science lesson, the learning completeness increased from 62.5% to 70%. While in BahasaIndonesialesson, the learning completeness increased from 70% to 75%. The findings in this research indicated that during group discussions some students still did not want to express their opinions. Besides, there were students who did not want to be in a certain group because they didn't like their group mates and wanted to make a group only with their close friends. It can be concluded that Team Assisted Individualization (TAI) learning model can increase the fifth-grade students learning interaction and achievement in Theme 7 at elementary school 3 Tambaksogra