Abstract: Abstract: In order to solve the problems of violent vibration, short time between failures and poor reliability existing in the crawler-type rice combine in China, experiments were conducted to analyze the characteristic of vibration source on combine World Dragon 280. 8 measuring points of engine support, cutter drive shaft support, vibrating sieve drive shaft support, drum support I, drum support II, chute driving wheel support, fan shaft support, and seat support were marked on the combine. Time-domain signals and frequency spectral characteristics of 8 measuring points were measured and analyzed by 5902 dynamic signal analytical systems in 5 different conditions such as no-load mode of engine, no-load mode of the whole machine and field harvesting. The result shows that up-and-down vibration of the engine, before-and-after vibration of the vibrating screen and left-and-right vibration of the sickle are the main causes of whole machine vibration, and Rotary motions of conveying mechanism, fan and threshing cylinder contribute secondly to the vibration of the whole machine. During harvesting in the field, vibration strength of the whole machine decreases and vibration strength of 7 measuring points decrease remarkably except for seat support. On full throttle no-load mode the vibrating frequency of engine is 71.78Hz, excitation frequencies of vibrating sieve, cutter, fan, drum I and drum II are 6.35 Hz, 8.79 Hz, 19.04 Hz, 12.70 Hz and 23.44 Hz separately. During harvesting in the field, several excitation frequencies of the main working parts overlap and it is difficult to identify. The research result provides a reference for improving driving comfort level and working reliability.