We evaluate nitrogen oxides pollution in Takamatsu and Utazu area in Kagawa prefecture, Japan. Annually observations for nitrogen oxides (nitrogen dioxide; NO 2 , nitric oxide; NO) (1990-2007) were obtained from data base of Kagawa prefecture, Japan. Changes in NO 2 and NO in Takamatsu and Utazu area were evaluated and compared. In 2007, NO 2 , NO and NO 2 + NO (ppm) in Takamatsu area were higher than those in Utazu area. However, NO 2 /(NO + NO 2) in Takamatsu area was lower than that in Utazu area. From 1990 to 2007, mean of NO 2 in a day over the level of 0.06 ppm was 30 days in Takamatsu area and only one day in Utazu area. Mean of NO 2 , NO and NO 2 + NO was significantly higher and NO 2 /(NO + NO 2)was lower in Takamatsu area than that in Utazu area. In addition, NO 2 , NO and NO 2 + NO were negatively correlated and NO 2 /(NO + NO 2) was positively correlated with years (1990-2007) in Takamatsu area. The level of nitrogen oxides pollution in Utazu area was lower than Takamatsu area. Further observation is required for preventing nitrogen oxides pollution in Kagawa prefecture, Japan.