This study was performed to understanding on guidelines for using therapeutic modalities according to injury phases of soft tissue. Clinical decisions on how and when therapeutic modalities may be used should be based on recognition of signs and symptoms, as well as some awareness of the time frames associated with the various phases of the healing process. The physical therapist must have a sound understanding of that process in terms of the sequence of the various process of healing stage. The results of this study are as follows: 1. Once an acute injury has occured, the healing process consists of the inflammatory response phase, the fibroblastic-repair phase, and the maturation-remodeling phase and can impede by various pathologic factors. 2. Modality use in the initial acute injury phase and the inflammatory response phase should be directed toward limiting the amount of swelling and reducing pain. 3. Modality use in the Fibroblastic repair phase may be change from cold to heat. The purpose of heat is to increase circulation to the injured area to promote healing. 4. During the Maturation-Remodeling phase, some type of hating modalities, ultrasound, or short wave and microwave diathermy should be used to increase circulation to the deeper tissue. In this phases, physical therapists must control training and conditioning habits to allow the injury to heal sufficiently.