Natural gas, coal and oil are the three main raw materials for the production of fertilizers, usually called gas head, coal head, oil head, three categories, because the oil and coal price increases far more than natural gas, so according to the cost advantage of the gas head, coal head, oil head. For example, 07 gas head Enterprise urea gross profit margin of 47.1%, and coal head enterprise Hualu litre urea gross margin of 21.5%.