The invention discloses a masonry cement with high strength and water retention. According to the weight percentage, the masonry cement consists of 21-98.99 percent of porland cement clinker, 0-50 percent of blending materials, 1-12 percent of gypsum, 0.01-2 percent of cellulose ether and 0-15 percent of other additives. With the cellulose ether of high water retention material added, the water retention of the masonry cement is greatly improved. At the same time, through breaking through the limitation that the using amount of the blending materials in the original masonry cement is not less than 50 percent, the using amount of the blending materials is lowered to be 50 percent below to improve the strength of novel masonry cement. The strength of the prepared masonry cement is high, and the masonry cement with the strength grades of 12.5, 22.5, 52.5R, 62.5, 62.5R, etc. can be made. The hard problems of using low-grade blending materials to produce masonry cement with high water retention and using low- grade strength masonry cement of 12.5 and 22.5 to produce high-grade strength building mortar are solved.