Internet of Things (IoT) provides context-aware intelligent services through the various data and connected devices. Also, the Social Network Services (SNSs) accelerates the sharing information among user. In this situation, trust management is a key feature for reliable services. This paper discusses trust issues about IoT and SNSs. Also, we define the trusted cross-domain metadata model that consists of the trust model, usage model and relational model. To evaluate trust of the service entities (agent, resource), we propose the trust evaluation method that considers measurable trust properties (e.g., social relation, usage information, agent and trust profile, explicit rate, etc.). Finally, we perform simulation of the proposed trust evaluation method based on the example scenario.