The investigations show that the focus of attention plays an important role in performing different motor skills. The purpose of this investigation was to study the effects of task difficulty and instruction on focus of attention in performing balance task in junior high school students. A total of 60 boys and 60 girls were randomly placed in two easy and difficult task groups (30 subjects each). An equal number of each group (10 subjects each) was randomly assigned in two experimental (external and internal attention) and one control groups. The subjects in easy and difficult groups performed balance tasks in a 6 attempts for 15-second. A digital balance meter and an air cushion were used to measure easy and difficult balance skills respectively. The results ANOVA showed that girl students didn’t show significant differences at p<0.05 when performing the easy and difficult balance tasks receiving instruction on external and internal focus of attentions. Also, there wasn’t a significant difference between girls in external and internal experimental groups performing difficulty balance task when receiving instruction on focus of attention. The results of ANOVA, however, were different when boys compared with the girls. The boys showed significant different balance skill in easy and difficult tasks. No significant difference was found between the boy subjects receiving external and internal focus of attention instructions. Therefore, it is to suggest that physical education teachers should pay attention to these psychological factors in teaching simple and difficult motor tasks to their students.