This article provides the case study report of Animal Assisted Therapy(AAT) in Hongcheon Elementary School. The program was conducted for once a week a total of 15 session form July to September and performed with 8 Students from the first grade to the fifth grade, 3 AAT therapists, 3 assistant therapists, 3 pet partners and 3 therapy dogs. The AAT program was titled as “Happy You & I with companion dogs” and performed for 3 school grade groups. The content of AAT program was designed to improve main psychological issues of students in 3 groups. 5 sessions of a total 15 sessions was conducted for a integrated group and other 10 sessions was for each group. STAIC, HTP and KFD were done as assessment scales for the first and the second grade students and Self-concept scale, CDI-C, STAIC, HTP, KFD and SCT was done for the fourth and the fifth grade students. As the results of pre-and post-test, We found the positive improvement in psychological symptoms of students.