ABSTRACT: Several experiments were carried out to investigate the effect of curing time and water to grout ratio on the ultimate load capacity of fully grouted rock bolts subject to pulling out loads. For this purpose, various samples were cast with water to grout ratios of 30%, 36% and 40 %. Pull-out tests were conducted on samples with different curing times, ranging from 7 to 28 days. Results indicate that the peak value of the pull out load increased as curing time increased. In contrast, increasing water to grout ratio weakens the pulling out resistance of fully grouted rock bolts.