The purpose of this study is to research the actual condition of working environment, working clothes and personal protective equipments on workers at a construction site in winter. The one to one interview by questionnaire was performed with 33 males and 2 females workers of a construction site in Daegu at $1.3^{circ}C$ air temperature, 28% R.H., 4.7m/sec air velocity. The questionnaire consisted of 21 questions including 4 personal characteristics questions, 12 working environment/performance questions and 5 working clothes/personal protective equipments questions. It was modified from the original questionnaire developed by Finnish Institute Occupational Health. We found that physical stress of workers increased and the ability of performance decreased. The workers felt the coldest at hands/fingers, feet/toes and the face part of cheek, nose and ears. They rarely wore thermal clothing for winter and answered that the thermal gloves for winter did not provided enough warmth. Even if the workers recognized the necessity of personal protective equipments for their safety, they did not wear them for efficiency of working performance. These results will be useful elementary materials for development of working clothes and personal protective equipments from the viewpoint of improving both working performance and comfort.