to provide you with the function of cracking down on trademark infringement: careful investigation and comprehensive collection of evidence materials are important prerequisites and guarantees for cracking down on infringement and achieving success. During the investigation, we should make full use of various investigation resources and adopt various flexible investigation forms to obtain a hidden, in-depth and accurate investigation effect. In particular, we should obtain accurate information on the following elements: infringer, specific forms of infringement, quantity of infringing goods, The evidence to be collected for the exact location of the infringing act (or infringing goods) includes: (1) proof of prior rights of the infringed (including trademark registration certificate, etc.) (2) samples of the infringed products (3) samples of the infringing products (4) proof of purchasing the infringing products (such as invoices, etc.).