Tunnel bracket is used in railway tunnel area in order to maintain insulation. Insulator performance evaluation test is proceeded refer to IEC 61109 but it is impossible to reflect all the field condition where insulator installed. Korea has clear four season in climatic condition and peninsula with lots of mountain in geomorphology condition. Tunnel bracket material which used in korea are butyl rubber, polymer and silicone. Most of them were installed without any internal climatic and geomorphology condition. According to the KORAIL operation data most of the insulator break down occurs in tunnel. So interval of inspection period is shorter then any other insulator and lots of maintenance cost incurs. Most major railway advanced country such as germany and japan maintain tunnel bracket with their own experience. For example visual inspection carried out with in one or two years and detailed inspection carried out between three to five years. This paper analyzed materials and shapes of tunnel bracket to in order to find optimized one in korea peninsula. Proposed bracket were tested under regulation and experience field data. Finally it was installed at the field and evaluated until now.