Targeting four male and female children aged 7 to 9, this action research aims to improve gender differences in art activities and an instructor’s female-biased instruction affected by the female bias of art teachers. After a pre-class(Session 0), the overall instruction plan was designed. During the second class(1·2·3), the third class(4·5·6) and the fourth class(7·8), recorded videos were transcribed to analyze discourses and reflect on the teacher’s utterances. First, discourses and completed works showed gender differences. Second, there was a female-biased instruction to convey ‘femininity’ through feedback defining ideal behaviors of students at school. The utterance was mostly provided to male children and after the teacher’s ‘perception’, it was improved. A new study result is that the female instructor made gender-typed utterances containing sexual stereotypes too. This study has significance by demonstrating that when a female instructor introspects her female-biased instruction, improvement starts.