Corrosion-induced concrete cover cracking generally experiences two stages: initial stage when cracks are developed from the bar until reaching the concrete surface; propagation stage in which cracks connect and widenon the concrete surface. A lot of studies have been conducted & to investigate corrosion-induced concrete cracking. However most of them focused on the initiation stage and less work was done on the propagation stage particularly on the relation between the crack width and the mass loss of steel bars. The relation between the concrete crack width and the mass loss of steel bar is not deterministic due to the variation of environmental parameters such as temperature moisture availability of oxygen and the nonhomogeniety of concrete cover passive film and metallurgical properties of steel bars. Therefore probabilistic method will be more realistic than the deterministic approaches.In this study the relation between concrete crack width and corrosion-induced mass loss of steel bar was studied in a probabilistic way. Concrete block specimens containing steel bars were prepared and subjected to accelerated corrosion test. Three concrete cover thicknesses were considered including 25.4 mm 50.8 mm and 63.5 mm. The accelerated corrosion tests were terminated when the corrosion of steel bar reached to different levels ranging from 0% to 30% mass loss. After & tests the crack width distribution along its length on the concrete cover was measured with a crack meter and the steel bars were took out of the concrete blocks and cleaned with a sand blaster. The cleaned steel bars were scanned with a 3D laser scanner and the residual cross-sectional areas along the length were determined. For a fixed corrosion loss of steel bar the corresponding crack width on the concrete surface was fitted with a probability density function (PDF). Similarly the area loss of steel bars was also fitted with a PDF for a fixed crack with. Probabilistic analysis results showed that normal distribution function best fitted the distribution of both crack width and mass loss of steel bar.& The mean crack width on the concrete surface increases logarithmically with an increase in the corrosion-induced mass loss. For a fixed& corrosion induced mass loss the mean crack width decreased with an increase in the concrete cover thickness.