With the rapid development of virtual reality hardware, virtual tours in galleries and museums are more and more popular in recent years. However, users sometimes get lost in the virtual space and miss displaying items during free exploration of the virtual scene. Therefore, proper navigation assistance is very important to help the user finish the tour and concentrate on the exhibits. Embodied agent can help users explore the scene effectively with higher interactivity and enhance user presence, but it cannot ensure completeness of visiting.In this paper, we investigate the effect of embodied agent on providing navigation assistance in virtual environments. We focus on the motion control of the agent and experiment on different speed, stay time and interactivity settings of the agent. The result shows that interactive agent can enhance visiting completeness and user presence. With these findings, we provide important considerations for the design of embodied agent for navigation in virtual environments.