[Objective] This study aimed to investigate the variation characteristics of Yunnan and Korean japonica rice quality under different environmental conditions in Yunnan Plateau. [Method] Ten Yunnan japonica rice varieties and six Korean japoni- ca rice varieties were selected to investigate the effects of ecological conditions on grain quality characteristics and starch RVA profile characteristic values of Yunnan and Korean japonica rice. [Result] The coefficient of variation of Yunnan and Korean japonica rice reached the maximum in setback viscosity （SBV）. The coefficients of variation of brown rice length （BRL）, chalkiness rate （CR）, amylose content （AC）, protein content （PC）, alkali digestion value （ADV）, final viscosity （FLV）, setback vis- cosity （SBV） and peak time （PET） of Yunnan japonica rice varieties were significant- ly higher than those of Korean japonica rice, while other grain quality characteristics were contrary. With the increasing altitudes, BRL, brown rice width （BRW）, length- width ratio （L/W）, whiteness （WH）, AC, ADV, FLV and consistence viscosity （CTV） of Yunnan japonica rice and BRL, BRW, WH, PC, peak viscosity （PKV）, hot viscosi- ty （HTV） and breakdown viscosity （BDV） of Korean japonica rice were significantly reduced , while CR, PC, HTV and PeT of Yunnan japonica rice and L/W, AC, ADV and CTV of Korean japonica rice significantly increased, but CR of Korean japonica rice showed no significantly variation. PKV, BDV and pasting temperature （PAT） of Yunnan japonica rice and PaT of Korean japonica rice showed an upward trend af- ter an initial drop with the increasing altitudes, while SBV of Yunnan japonica rice and FLV and PeT of Korean japonica rice were contrary. [Conclusion] This study provided theoretical basis for breeding of japonica rice in Yunnan Plateau.