Although PVC is very similar to LLDPE, there are some differences. LLDPE is produced on the basis of ethylene, and its raw materials are relatively simple, belonging to crude oil chemical industry. In China, PVC has two kinds of raw materials, one is crude oil, and like LLDPE, it is made of ethylene. The other is coal. When the domestic market price fluctuates, the rhythm of price fluctuation is different, especially from the end of last year to this year, the resilience of coal is very strong, and the domestic calcium carbide method accounts for three quarters, which shows that the cost rigidity of PVC is very strong, while the rigidity of LLDPE is much weaker, and the decline rate of LLDPE is definitely much larger than that of PVC. The same rising process, but different. In addition to basic raw materials, there are other aspects such as chlorine. Because the output and cost structure are different, we can't simply equate the prices of the two varieties in the market, but we should know the market situation of each variety in detail.