||The subgrade is layer of natural soil prepared to recieve layers of pavement. The thick ness of pavement depends upon properties of the subgrade.Subgrade soil strength is evaluated in turns of CBR and used for design of flexible pavement.CBR is labourous and time consuming,even though it is used as a widely acknowledge performance parameter. It is also very difficult to prepare sample at desired in situ density for laboratory testing.As dynamic cone penetrometer is a low cost , portable equipment, it is used for quick determination of subgrade soil strength. One of the major advandtages of the test is that the pavement is tested in the condition at which it performs. The simplicity of the test allows repeated testing to minimise errors.For Laboratory investigation specimens were fabricated at optimum moiture content and maximum dry density obtained from hevery compaction caracteristics.Correlations are developed using regression analysis to estimate subgrade soil strength in terms of CBR values for unsoaked and soaked conditions using laboratory testing results of dynemic cone penetrometer.