摘要：利用1978～2004年共27年数据研究发现，我国三大产业发展速度之间存在紧密的内在联系，从系统动力学的角度而言，某个产业其发展不仅与该产业前期的发展有关，而且受其他产业同期和前期发展速度的影响。从脉冲响应函数和方差分解的结果可以看出，以农业为代表的第一产业的重要性最为明显，农业的发展对本身发展以及第二、第三产业的发展都十分重要。  

    Abstract: By using the data from year of 1978 to 2004(total 27 years), it is found that Chinese three main industries have a close inherent link.From the perspective of system dynamics, an industry development is not only related to the preliminary development of the industry but also related to the early stage and the same period development speed of other industries.From the impulse response function and variance decomposition results, it is found that the importance of chief industry represented by agriculture is very clear. The development of agriculture is very important to the develoopment of itself, and secondary, tertiary industries.