Disclosed are a mixed catalyst, a method for preparing same, a method for forming an electrode by using same, and a membrane-electrode assembly comprising same, the mixed catalyst having uniform physical features within a predetermined range, which are suitable for the manufacture of an electrode and membrane-electrode assembly having desired performance and durability. The mixed catalyst comprises: a first catalyst, which includes a first support and first catalyst metal particles distributed on the first support, and has a first BET surface area and a first total pore volume; and a second catalyst, which includes a second support and second catalyst metal particles distributed on the second support, and has a second BET surface area different from the first BET surface area and a second total pore volume different from the first total pore volume.