Abstract: It is very important to compressive strength of concrete that the concrete is in the optimum curing condition. It is discussed how the humidity, temperature and age of curing influence the compressive strength of concrete in this text. It is elicited that humidity of curing is the most influence on compressive strength of concrete. The early curing is the optimal way to enhance compressive strength of concrete. The compressive strength of Fly ash concrete is the most sensitive to different curing conditions.