The purpose of this experimental research was to study the effect of a guidance set on unity of prathom suksa v students of Banthakloi School in Gingamphoe Thatakeab, Changwat Chachoengsao in the academic year 1994. The 20 subjects were randomly selected from students whose unity were lower than 25 percentile. They were randomly divided into the experimental group and the control group. Each group was consisted of 10 students. The experimental group was exposed to a guidance set while the control group was taught with the conventional instruction. The instrument was unity questionnaire. The data were analyzed by t test. The results were as follows : 1. The unity aspect of the students who were exposed to a guidance set was singificantly higher than before the experiment at .05 level. 2. The unity aspect of the students who were taught with the conventional instruction was significantly higher than before the experiment at .05 level. 3. The unity aspect of the students who were exposed to a guidance set was significantly higher than those who were taught with the conventional instruction at .05 level.