This study aims to illustrate how imagination functions in the painting of sixth graders in elementary school. Thirty-five sixth graders are assigned to keep track of their creative experiences while doing eight pieces of imaginative painting. The process, the characteristics of imaginative activity and the factors affecting imagination are observed and analyzed. The results of this study are listed as follows: (1) The implementation of imagination in the creative painting of sixth graders is divided into three phases: the beginning, modification and the end. Imagination is implemented either through divergent thinking, or convergent thinking. (2) Imagination applied in the creative paintings of sixth graders is characterized by association by external similarity with relational thinking and creative recombination of existing elements. (3) There are internal and external factors affecting imaginative activity.