In a video transmission system, a video transmission device includes circuitry configured to determine an attention position where a viewer located in a second space is estimated to pay attention to a situation in a first space, divide a range included in a recorded video of the first space into multiple regions including at least a first region having the attention position and a second region, set a first video quality for the first region and set a second video quality lower than the first video quality for the second region, generate video data in accordance with the first video quality and the second video quality, and transmit the video data to a video output device. The video output device includes circuitry configured to control a display unit using the video data such that the display unit displays a video showing the situation in the first space.