Laboratory tests have been conducted on 8 full-size simply-supported reinforced high strength concrete (HSC) beams. For each beam, the instantaneous and residual crack widths at different load levels were measured. In addition, each beam was subjected to free vibration tests in which the logarithmic decrements of damping corresponding to various residual crack widths were recorded. The authors have previously published some empirical formulas for the prediction of average and maximum crack widths, as well as logarithmic decrement of damping in reinforced normal strength concrete (NSC) beams. Comparisons with test results from all the 8 HSC beams indicate that these prediction formulas may also be applicable to HSC beams.