This paper summarizes the development of PetroChina's ethylene business in 2023, including the ethylene production, ethylene yield, yields of ethylene and propylene, processing loss ratio and energy consumption of its subordinate petrochemical enterprises, as well as the feedstock optimization, long-term operation, maintenance, technical modification and technical measures. The focus of work concerning long-term optimum operation of ethylene plants in 2024 is put forward.