The purpose of the study was to examine the effects of a reality group therapy guidance program on learning attitude and achievement of fifth- and sixth-graders who were underachievers in Mandarin. Quasi-experimental design was applied in this study which consisted of an experimental group and a control group. Participants of the study completed The Learning Attitude Inventory (LAI) and provided their grades of Mandarin three times as the pretest, posttest, and six-week follow-up test after completion of the fifteen-week therapy program. One-way ANCOVA or Johnson-Neyman analysis indicate that: (a) the reality therapy group guidance program has an immediate and continuous positive effect on the learning motivation of participants, (b) the reality therapy group guidance program immediately improves learning attitude, motivation, and strategies of participants with average or below-average achievement in Mandarin, (c) the reality therapy group guidance program continuously enhances learning attitude, motivation, and strategies of the participants in the follow-up test, and (d) the reality therapy group guidance program an immediate, but not continousl, positive effect on the participants’grades in Mandarin.