Disclosed are a 5-(2,6-dioxyphenyl)tetrazole-containing polymer, a method for preparing the same, a membrane containing the same and an electrochemical device, particularly a high temperature polymer electrolyte membrane fuel cell, including the membrane. The membrane containing the 5-(2,6-dioxyphenyl)tetrazole-containing polymer is capable of providing high proton conductivity and exhibiting good mechanical properties, thereby capable of providing superior fuel cell performance. Accordingly, the membrane may be usefully used in an electrochemical device, particularly a fuel cell, more particularly a high temperature polymer electrolyte membrane fuel cell.