The purpose of this study is to develop and apply effective teaching strategies and program for the gifted-in-science. The teaching material for the gifted students was focussed on microscope. This study consists of three steps according to the enrichment triad model of Renzulli. Firstly, the gifted students investigate and express themselves for theological backgrounds, for examples, kinds, structure and use in various ways of microscope. It is to provide basic data for the effective ideas and interest which help students have the appropriate microscopic conceptions. In the second step, it contains understanding of a term and function of microscope, making of simple microscope, principle of a statue focusing and size estimation of an outline of subjects by scientific investigation activity. Lastly, it focussed on enlargement of post-learning through investigation of relationship with inter-science and experiments using microscope. Therefore, it was concluded that this study may help teachers reconsider scientific program development for the gifted or enriched students and to be successful in the teaching-learning processes.