Abstract: To explore high-yielding cultural techniques of ratoon rice with machine harvest and observe on growth characteristics of ratoon tillers, the combination tests of different nitrogen application time were set. The results showed that the main tillers located at the second and third node order in ratoon season with few total leaf number, no independent root, early breeding and early maturity after the main rice was harvested by hand in high cutting. While the main tillers located at the fourth and fifth node order in ratoon season with more total leaf number and independent root after the main rice was harvested by machine in low cutting. After machine harvest 7~10d, nodal root and tillers germinated at prophyll node. After machine harvest 9~12d, the first panicle branch differentiated. The heading and ripening stage delayed about 15d than that of the field which the main rice was harvested by hand in high cutting. After the main rice was harvested by machine, early and heavy application of N-fertilizer effectively promoted root, bud germination and branch, spikelet differentiation of ratoon tillers, which can increase yield significantly.