Abstract: This study designed to explore the relationship between flower color and petal epidermal cells shape in Phalaenopsis. Scanning electron microscopy (SEM) was used to explore the petal microstructure differences of Phalaenopsis. According to the Royal Horticultural Society Color Chart (RHSCC), flower color of 8 evenly colored flowers were grouped into four classes: white, green-yellow, purple and purple-violet. In this research, evenly colored flowers, including two white samples, three green-yellow samples, two purple-violet samples and one purple sample, four purple-blotched flowers with white ground color and yellow ground color were studied using SEM, respectively. Three different parts, including yellow or white ground color parts, purple blotch parts and the junction of the ground color and the over color, in the blotched flowers were observed. In addition, transverse section from the middle of the petal of the junction of the ground color and the over color in each spotted flowers were taken using a sharp razor blade, mounted in 0.25% PEG solution which had an osmotic potential close to that of petal cells, and examined using a Zeiss microscope. [Result] The two white flowers had papillate epidermal cells, all the other 10 flowers had dome-shaped epidermal cells. In addition, there was a small amount of pores in the petal epidermis of some samples. The epidermal cell shape of the same color from the different varieties of Phalaenopsis petals may be different (papillate or dome), but the cell shape in different color regions of the same petal is the same. These finding prove that flower color, no matter ground color or over color, is not the determinant effect of the petal epidermal cell shape in Phalaenopsis. The above comparisons study between different color Phalaenopsis will provide some reference for the future research about color in Phalaenopsis.