electronics, textile and defense industries as the backbone, Xi'an has formed a modem industrial production system with many types of light industry, chemical industry, food, metallurgy, construction materials, electric and medical production, etc. Her industries such as high-voltage transmitting and transforming electricity equipment, airplane manufacturing, electronic and communication equipment, automation instruments, petroleum prospecting instruments, optical instruments, refrigeration equipment, railway tanker, wristwatch and sewing machine, etc. are among the best in the country.