Abstract: The effects of aggregate gradation on lime-fly ash bound macadam’s compression strength in varied ages were analyzed.The direct-vision and variance analysis were adopted in indoor tests.The result indicated that the aggregate gradation has a remarkable effect on the compression strength.The early strength is higher with bias-coarse gradation while the later strength is higher with bias-fine gradation.When the aggregate has no grain finer than (0.6 mm),there is an optimum content of aggregate which makes the highest strength.The bigger the size of intermittent division in discontinuous gradation is adopted,the higher the strength becomes.