This paper analyzes the impact of the rise and decline of the oil prices on the agricultural diesel prices, and interviews the reasons and effects. The results show that the rise of the oil price is the major factor that impacts on diesel price change, that is to say, the price of diesel oil price goes up with the rise of oil price, however, it does not fall with the decline of oil price in short term. Possible explanations for these results are offered. The most important one is that the monopoly market structure of agricultural diesel and oil is the main reason why the agricultural diesel price responds asymmetrically to oil price change. And it gives some advice to find out a way to cope with the inconsistency between agricultural production and the oil price.