Most of the car navigation systems provide 2D or 3D virtual map-based driving guidance. Oneof the important issues is how to reduce cognitive burden to the driver who should interpret theabstracted information to real world driving information. Recently, an augmented reality (AR)-based navigation is considered as a new way to reduce cognitive workload by superimposingguidance information into the real world scene captured by the camera. In particular, head-updisplay (HUD) is popular to implement AR navigation. However, HUD is too expensive to beset up in most cars so that the HUD-based AR navigation is currently unrealistic for navigationalassistance. Meanwhile, smartphones with advanced computing capability and various sensors arepopularized and also provide navigational assistance. This paper presents a research on cognitiveeffect and responsiveness of an AR navigation by a comparative study with a conventionalvirtual map-based navigation on the same smartphone. This paper experimented bothquantitative and qualitative studies to compare cognitive workload and responsiveness, respectively. The number of eye gazing at the navigation system is used to measure the cognitive effect. Inaddition, questionnaires are used for qualitative analysis of the responsiveness.