In this demo we present SemanticCT, a semantically-enabled systems for clinical trials. SemanticCT is built on the top of LarKC, a platform for scalable semantic data processing. SemanticCT has been integrated with large-scale trial data and patient data, and provided various automatic services for clinical trials, which include automatic patient recruitment service (i.e., identifying eligible patients for a trial), trial finding service (i.e., finding suitable trials for a patient), and trial feasibility service (i.e., analyzing possible recruitment at design time).