The purpose of this study was to find out how outdoor sand play activities with natural object affects children s nature-friendly attitude. The subjects of this study were 31 children (aged 3 4 5) attending two public kindergartens which are located in Gangwon-do. The experimental group was selected from 15 children (two 3-year-old, four 4-year-old, nine 5-year-old), the control group from 16 children (four 3-year-old, two 4-year-old, ten 5-year-old). The outdoor sand play activities using natural objects were administered to the experimental group, while outdoor sand play activities using artificial sand tools were administered to the control group. The experimental treatments had been conducted by the researcher 3 times a week for 8 weeks from August 25, 2014 to October 16, 2014, totalling 24 sessions. To inspect children s nature-friendly attitude, a research tool was used an improved 「A Test Nature-Friendly Attitude」by Lee Sung-min(2012) from the adapted and modified version by Lee Mi-hye(2009) based on CATES-PV(The Children s Attitudes Toward the Environment Scale-Preschool Version) by Musser and Diamond(1999). The results of this study were as follows; The outdoor sand play activities with natural object lead to statistically significant differences in the nature-friendly attitude of children(p< .001). This implies that the outdoor sand play activities with natural object have positive effects on the nature-friendly attitude of children.