The fairness of agricultural science and technology resources allocation is significant for improvement of agricultural science and technology resources allocation ability. This paper analyzed the regional difference on the allocation capacity of agricultural science and technology resources in China, and then we decomposed its influence factors with Dagum Gini index. The results showed that, firstly, there was significant difference in agricultural science and technology resource allocation ability. 17 provinces had a decline trend in agricultural science and technology resource allocation ability. In the 6 ecological districts, the allocation ability of agricultural science and technology resources also were on the decline trend in northeast and northwest areas. However, other 4 districts had an increase tendency. Secondly, on the whole, there was a decreasing tendency in the fairness of agricultural science and technology resources allocation. But it showed remarkable different trend in different time stages. Thirdly, no matter inside one area or between districts, agricultural science and technology resources allocation fairness had significant difference. And the difference between districts was the main source leading to the difference in national agricultural science and technology resources allocation ability.