Snow fungus (Tremella fuciformis) with functional contents has satisfactory effects on various diseases, including atherosclerosis, high cholesterol, healthy skin, cancer, diabetes, and anti-inflammation. In this study, the extraction yield and functional contents (ergothioneine and β-glucan) of white jelly fungus were compared based on the extraction conditions using response surface methodology. Results revealed the extraction conditions for optimization of the dependent variables to be 60oC and 4.33 h, when 16.6 mg/mL of sample concentration was used. Under these conditions, the extraction yield was 24.9%, including ergothioneine (66.8 μg/g) and β-glucan (34.9 g/100 g). These results can be useful in understanding the functional ingredients and mass extraction process in mushroom.