At present, there are four collagen suture manufacturers, namely Shandong Boda, Jiangxi Longteng, Loudi Zhongyuan and Hunan Ranyuan. Among them, Shandong Boda and Jiangxi Longteng may contain collagen, but they are actually similar to catgut, and they are made of green goats, which need protective liquid to protect them. Weak tension is their fatal weakness, and their defects have been exposed in clinic. Hunan Ranyuan and Loudi Zhongyuan are the same product, both of which are animal tendon tissues with strong tensile force and good absorption effect. They can be said to be real collagen sutures, but there are many negative and unstable information in Ranyuan, Hunan, such as lawsuits and infringement disputes, which make many agents flinch. Loudi Zhongyuan has no negative information at present. Since it was approved, it has taken the lead in passing many certifications of GMP and ISO series. The starting point is much higher than that of Hunan Ranyuan, and the product quality is reliable and worth relying on.