The goal of this study is to investigate the effect of ecological experience program at the urban stream on the environmental sensitivity of elementary school students. In order to perform this study, two classes of 6th graders of M elementary school in Gwangju were selected and divided into two groups; one groups was the experimental group that undergoes ecological experience program at the Gwangju River, and another group was the control group that studied about environment in the classroom. The results of this study were as following. First of all, the experimental group has more influence on the environmental sensitivity than the control group. Secondly, the ecological experience program at the urban stream can be the effective method to build the environmental sensitivity of elementary school students. In conclusion, the results are showing that the ecological experience program at the urban stream helps elementary school students to change their environmental sensitivity in positive ways, also it gives idea that how to protect the environment and what they actually can do.