We analyzed the concepts on plant taxonomy to provide basic information for teachers` instruction and for further editions of biology textbooks. The middle school textbooks contain much knowledge of several plant divisions, taxonomic keys, application of taxonomic lessons to practical fife, and edible plants. However, explanations on species diversity is insufficient., requiring development of effective instructional materials and methods. The high school textbooks lack contents on flowering plants that are dominant organisms on the earth. To increase understanding of species diversity. campus can be used as field garden. In addition, it is necessary to mention rare plants, carnivorous plants, and plants going extinct for students to be aware of fragility of our nature. Therefore, both field classes - for direct contact with nature - and usage of visual instruments such as slides - for indirect exposure to nature - are required to improve the effeciency of biology classes.