Ethylene is the basic raw material of petrochemical industry and vital to a country’s manufacturing industry. The self-sufficiency in China had been around or below 50% before 2021, there is a big gap between ethylene capacity and its equivalent demand. That’s why ethylene self-sufficiency has frequently mentioned and emphasized in every five-year plan in China. The massive investment in 2020-2026 will help China to improve self-sufficiency to 89% in 2026,but still not 100% yet. Is it feasible for China to reach 100% self-sufficiency before 2030? How much is the gap and what’s the limitations that need to be overcome? What will happen if China reaches 100% self-sufficiency in 2030? In this insight, we will address these questions.