Variation of quality of five kind of recent cement was investigated. As a result, the following conclusions were obtained. (1) Each cement had a stable performance in the density, the heat of hydration, the specific surface area, and the compressive strength. (2) The ignition loss of each cement was very little compared with requirement quality of JIS. (3) As for the ordinary portland cement and the Type B portland blastfurnace slag cement of each cement producing company, the chloride ion showed the tendency to increase. (4) As for the Portland cement of each cement producing company, the total alkali content showed the tendency to decrease.
