This study investigated educational effects of soil play activities by analyzing the influence of soil play activities on children's nature-friendly attitudes and emotions. Fifty 5-year-old children enrolled in K-kindergarten in Y-city were randomly selected for the study. Assessment of nature-friendly attitudes and emotions was by 11 questions selected from Musser & Diamond's (1999) Pro-environmental Attitude Test (adapted by Lee, Hye Sun, 2006) and from Bar On and Parker's (2000/2001) Emotion Test, an Emotional Quotient Scale for Young Children. Results showed that children who participated in the Soil Play Activities program acquired more nature-friendly attitudes and emotions than the control group. In conclusion, soil play activities can improve nature-friendly attitudes and emotions of 5-year- old children.