The purpose of this article is to introduce the radiotherapy acute skin reactions, factors which affect skin reactions and skin care products which might be used during radiotherapy. The skin reactions during radiotherapy include erythema, dry desquamation, moist desquamation and ulcer. Factors affecting the degree of skin reaction include both treatment-related factors and individual factors. The issues of skin care include: how to care radiotherapy skin, how to care erythema and dry desquamation, and how to care moist desquamation and ulcer. The most important issue for radiation oncology nursing is the skin reaction during radiotherapy. The oncology nurses make their efforts to improve discomfort and wound care of the patients might experience during radiotherapy. Through understanding of skin reactions and skin care during radiotherapy, then one could set up skin care standard in order to promote patient's comfort and wound healing.