This paper evaluated compressive strength of concrete using sea sand at Phu Quoc, Kien Giang province under various curing environment. Total 180 cube specimens were experienced under compressive test. Two types of concrete compressive strength were used, including grade 200 (M200) and grade 300 (M300). Replacement ratios of sea sand varied from 0, 50 and 100%. All specimen were cured in normal water and sea water for 7, 14, 28, 56 and 84 days. The results showed that the compressive strength of sea sand concrete grew rapidly from 7 days to 28 days but increased slowly from 28 days to 84 days. Among three different replacement ratios of sea sand 0, 50 and 100%, the specimens with 100% replacement of sea sand showed the highest compressive strength at 7, 14, 28 and 56 days, while the specimens with 50% replacement of sea sand showed the highest compressive strength at 84 days. The compressive strength increased from 2% to 35% with 100% of sea sand replacing normal sand. Most of specimens cured in normal water exhibited higher compressive strength from 2% to 34% than those cured in sea water.