The weathered sand from the Three Gorges Reservoir in Yichang city was stabilized by cement and was used for highway pavement base. Weathered sand was mixed with 3%, 5%, 7%, 9% cement, respectively, and maintained for 7 days, 14 days, 21 days,and 28 days under standard curing condition, and then test on the California bearing ratio(CBR) value of the treated weathered sand was carried out. Experimental result shows that cement can effectively improve the CBR value of weathered sand, and cement content and curing age both have great influence on the CBR values of weathered sand. Under the same curing age, the CBR value of cement-treated weathered sand increases with the growth of cement dosage gradually. CBR value and cement dosage shows good logarithmic relation. Under the same dosage of cement, the CBR value of cement-treated weathered sand increases with the growth of curing age steadily, and the relationship between CBR value and curing age is linear. In comprehensive consideration of economy and mechanical properties of weathered sand, adding 7% cement could maximize the CBR value.