Through out the 16th century and into the 17th century, Japan went through a period of a historic upheaval. Opinion is divided as to how to interpret this upheaval, but the dominant view is that the political power arriving afterwards established feudalism. During this period of great change, revolts called “ikki” broke out in various parts of the country. They arose especially in remote mountain areas and for this reason it has long been thought that these revolts were retarded ones caused by old rulers who mobilized peasants under their rule in order to maintain their retarded society, and that, in this sense, there is not much historical significance in these revolts. This paper intends to challenge thus accepted notion, focusing our attention on the fact that these revolts broke out in deep mountains and examining their historical significance.The paper has considered the cases of the Kitayama ikki in 1614, Shiibayama ikki in 1619, and lyayama ikki in 1620 as revolts in deep mountains in the early 17th century. What is common to all these theaters of revolt is, in the first place that the areas' economy was based on non-paddy farming, especially on slash-and-burn farming, in deep mountains. In the second place, these areas had been politically independent, considered as “area having no ruler”. Another common factor is that all the revolts were armed and ended in massacres.All these points suggest that these 17th century revolts were not the revolts of old rulers in retarded regions, but rather were an inevitable result of the process of ruling non-paddy cultivators of mountains by the unifying powers based on paddy cultivation in plains shown in the term “Kokudaka system”. Thus we can see the historical significance of these uprisings in the fact that they represented the resistance of mountain people to protect their own society.