The higher was the protein content, the lower was the amylose content, and the better was the eating quality of nonglutinous rice. In 1991—2006, the protein content (PC) and amylose content (AC) were examined in 15 areas of Hokkaido. The range of the yearly (regional) variation on the average of all areas (years) was 7.2%~8.6% (7.2%~8.2%) in PC, and 18.3%~22.2% (19.8%~21.2%) in AC. That range of the yearly variation in those AC, PC was 1.4, 2.8 times respectively, larger than that of regional variation. That was because the range of the yearly variation in the mean temperature during rice cultivation season, during of some growth stages and growth characteristics like grain yield was 1.6~4.4 times, larger than that of regional variation. Among years, the earlier the heading date, the higher the temperature during the sensitive stage to stelile-type cool injury; the lower the sterility, the heavier the 1 000-kernel-weight; and, the higher the grain yield, the lower was the PC. At 843 ℃ of the cumulative daily mean temperature during 40 days after heading (CTAH), the PC were lowest in the quadratic regression relationship. Those relationships wasn’ t clear in the area where is high wind speed during tillering, low available rate of soil nitrogen and poor initial growth, on the contrary, between PC and 1 000-kernel-weight a positive relationship was found. The regional variation of PC did not correlate with these growth characteristics, but the lower the ratio of peat soil in the paddy field and the lower the wind speed during tillering, the lower was the PC. On the other hand among both years and regions the earlier the heading date, the higher the CTAH, the lower was the AC. Among areas, the shorter distance from the sea, the lower north latitude and the smaller mean diurnal temperature range during 40 days after heading, the lower was the AC.