Abstract:In this paper, basis of Japanese labors work for a long time cause on the “karoshi” event, combing the government police on a question of “karoshi” step by step. Through the international comparison of labor time, male labors work for a long time, but the female labors work on the part-time job, this duality phenomenon is very common and helpless for unpaid overtime. Through the government department data appeared long time labor and labor time structure characteristics of the truth in Japan. To do unpaid overtime, discusses the causes of no paid annual leave. From the perspective of labor time reveals the cause on the problem of “overwork”. And the relevant legal regulation is discussed.