PROBLEM TO BE SOLVED: To provide a suture which is used for manufacturing a medical instrument including a suture fixation part such as a stent graft, an artificial blood vessel and an artificial heart valve, the suture enabling stitches and notches free from loosening to be formed while maintaining a fibrous shape and strength.SOLUTION: The suture for suture fixation of a medical instrument comprises two components of a high melting point component and a low melting point component, wherein a melting point difference between the two components is 30°C or higher, and wherein the low melting point component is exposed to a suture surface over the entire length direction. For instance, the suture is multifilament yarn in which a high melting point component filament 3 and a low melting point component filament 4 are combined. After a medical material made of cloth or made of a film is sutured with the suture, heating treatment is performed at such a temperature that the low melting component becomes meltable without melting the high melting point component, and the suture part is fused and fixed.
