Abstract. The purpose of this study was to examine the preservice chemistry teachers' understanding of periodic table concepts and some atomic properties. The study group of this study was comprised of 17 preservice chemistry teachers who were undergraduate students at a public University. The preservice teachers' ages are between 19 and 26, and the mean is 21.12 (SD=1.83). In addition, the 14 of the preservice teachers are female and three are male. In the study, concept maps and lotus blossom technique were used as data collection tools in order to determine the understanding of preservice chemistry teachers about the periodic table concepts. Data obtained through these techniques was analysed to figure out the useful of these assessment tools. The results of the analysis indicated that preservice teachers have limited understanding of the periodic table and its properties. In addition, at the end of the study, it was determined that they have many misunderstanding.