1. It was studied on the relations between the amounts of exchangeable manganese in soils and concentrations of salt solutions, temperature and time of treatments, the kinds of salts used for extraction and the air drying of samples. According to the results of the studies the determination of the exchangeable manganese in soils was performed as follows: fresh soil samples corresponding to 100 gm. of dry matter were shaken for an hour with 250 cc neutral normal potassium chloride solutions at room temperature and extracted manganeses were determined colorimetrically with periodite method. 2. In the amounts of the exchangeable manganese, soils from the rice field was more than upland field generally and G horizon was more than other horizons. I found no relation between the amount of the exchangeable manganese and the kind of parent material, pH values of soils or total manganese content. 3. The amount of extracted manganese increased with lowering the pH values of extracted solution. But its solubility curves were various figure. 4. The amounts of the exchangeable manganese increased rem a rkably when soils were stood in water lodged conditions.