Crystallization differentiation plays an important role in the study of earth science in high school by helping students to understand the diversity and the origins of igneous rocks. However, it is difficult for students to understand. So in order to improve their understanding, an observation lesson on crystallization differentiation was designed and put into practice with igneous rocks, specimens of zoned pluton. Students were divided into two groups: the experimental group which used a "one concept map" that described crystallization differentiation at the time of observation, and the co...