This article will be examined how an art teacher can be affected to the student's creativity and their art expression in the art classroom. The art program in school is mostiy studio work especially emphasizing on 2D(2 dimensional art work) because the usage of general classroom facilities, time limitations and lack of art equipment, and ate…. Therefore, many art classes are proceeded by the student’s making art wroke which don’t provide be depth is art. The attondence in this article is that if an art teacher’s active parucipation in the art classroom will be enourmously affected student’s art works in various ways and improved their art expressions, then, we are confronled what is the ultimate an art teacher’s role in the art classroom and how he/she has to be prepared and organized the art lessons? Lastly, the importance of evaluation of a student’s art work will be discussed. The spontaneous way to evaluave one’s work by himself/horself will help to develop not only the student’s sensitivity and creativity but also bring on the critical way to look, to see and to verbalize the one’s work. It is assumed that if the teacher is well-propared the art lessons and stimulate each student’s eurieusness, then every student in the classroom will have pleasure, satisfaction and confidence to express his/her thoughts and feeling without any hesitation.