Piles formed by tamped concrete are a kind of technology in foundation treatment. In order to study the difference of strength characteristics between tamped and ordinary poured concrete, optimum parameters of mix proportion on tamped concrete are obtained by heavy compaction test in laboratory, then unconfined compressive strength tests are accomplished on the basis of optimum parameters of mix proportion. Influence factors of strength characteristics of tamped concrete are studied, such as cement-aggregate ratio, curing age, curing condition and so on. Finally, strength characteristics of tamped and ordinary poured concrete are compared. The test results indicate that the tamped concrete is hardened quickly and early-strength. In standard, water and saturated soil curing condition, compressive strength all grows sufficiency, thus tamped concrete can be used in ground and underground environment. At the same time, a higher strength can be obtained by smaller cement content, and the cost of tamped concrete can be reduced effectively.