Normal tissues have sigmoid dose-response relationships. These relationships are reliably detectable in some clinical and many experimental situations through the aspect of radiobiology. By the way, when the group of patients are treated by radiotherapy combined with chemotherapy, the tolerance dosage of normal tissues in the group is not explained by biological aspect alone. Human tolerance which means the will of patient for the tolerance to the treatment, is the new concept. The compliance to take medicine is the second important problem, when the tolerance dosage of normal tissues in the group of patients treated with combined therapy are discussed. When these new concepts to the normal tolerance dosage, which are human tolerance and compliance, will be scored in the future, these factors will be discussed again about their importance.