Abstract: To thoroughly understand the agricultural economic growth origin in Guangdong Province as well as its four wide ranges in 1990-2008. The reckoning and analysis carried by the Solow complement law indicated: although the contribution rate of agricultural scientific and technological progress continues to increase, in addition to the Pearl River Delta, relying on increased material costs has always been more dominant position in growth mode input; labor contribution rate has been enhanced, but the instability has yet to be upgrading; the negative effects are arising from the reduction of cultivated land apparently. Consequently, it is proposed to increase the intensity of investment in agricultural science and technology, establish an efficient system of agricultural science and technology services to enhance agricultural technology and farmer education and training as well as strictly protect cultivated land, which is the key of agriculture economic growth of Guangdong Province now and in the future.