High gold content. According to the query of official website of Chang 'an University, it is because the acquisition of a doctor requires real talents and practical learning, not only a high cultural level, but also a high scientific research ability, which can achieve certain scientific research results. Chang 'an University is a 2 1 1 university. The major of road and bridge is first-class in China, and the doctoral degree graduated from Chang 'an University is highly recognized by the society.