Virtual reality (VR) applications have become popular recently and rapidly commercialized. The behaviors of users watching 360-degree omni-directional videos have not been fully investigated. In this paper, a dataset of view trajectories for users watching 360-degree videos over computer (desktop/laptop) environment is presented. The dataset includes view center trajectory data collected from viewers watching twelve 360-degree videos over the computer, using mouse to navigate and explore the environment. The selected videos cover a variety of contents, leading to different navigation patterns and behaviors. Based on the dataset, we demonstrate that the viewers share similar viewing patterns over certain 360-degree video category. We also compare the view motion patterns and statistics with prior datasets captured using head-mounted display (HMD). The dataset has been made available online, to facilitate the studies on 360-degree video view prediction, content saliency analysis and VR streaming, etc.