This paper reports the strength, water permeability and chloride penetration of concrete in which Ultra-Fine Natural Steatite Powder (UFNSP) is used as a replacement to cement. Concrete cubes and cylinders were prepared for compressive strength of 60 MPa. Mechanical strength, coefficient of permeability and average chloride penetration rate were studied, due to the replacement of ultra-fine natural steatite powder with cement at 5%, 10%, 15%, 20%, and 25% by mass of cement. The workability was achieved by incorporating modified polycarboxylic ether as super plasticizer. It is observed that the replacement of ultra-fine natural steatite powder of about 5%, 10% and 15% by weight of cement gives a considerable increase in strength during early ages. From 28 days of age changes in the mechanical properties of compositions up to 20%are marginal with respect to the Control Specimen. There is a reduction in mechanical strength of concrete with 25% of replacement of ultra-fine natural steatite powder. Also water permeability and chloride penetration decreases with increase in replacement up to 20%. The lowest water permeability and chloride penetration values were observed in 15% replacement during 90 days test. � Research India Publications.