In the traditional sense, the software trust mainly contains two aspects: security and dependability. There have been many different statements and studies about the conception of trust. From the perspective of IT system, ISO/IEC 15408 standard suggests that the behavior of a trusted components, operation or process is predictable under any operating conditions and can resist the damage caused by application software, virus and the certain physical interference; Trusted Computing Group think that if an entity always act according to the expecting set goals, it can be called trusted. From the perspective of network behavior, it is suggested that the trusted network should be that the behavior and its results of the network system can be expected, behavior state can be monitored, behavior results can be assessed, and abnormal behavior can be controlled. From the perspective of the user experience, Microsoft proposes that trusted computing is a safe and reliable computation which can be achieved at any time, and the degree of trust on computers from humans, just like the freedom and security which we can feel when we use the electric power system or a telephone; The trustworthy is also defined as that if a software system’s behavior is always in line with expectations, it can be called trustworthy. Different expressions about the concept of trustworthy shows people’s cognition of trustworthy at different times from different perspective and also represents the different research purposes and application domain.