An agent for visualizing vitreous body which is to be injected into the eye to visualize the vitreous body by a safe and sure method. The agent for visualizing vitreous body is prepared by using a high-molecule substance having a positively or negatively charged functional group and adding a hardly water-soluble and nonsteroidal colored substance, in which the high-molecule substance is to be suspended, thereto. Because of having a nonsteroidal nature, it can be safely injected into the eye and the colored substance, in which the high-molecule substance is to be suspended, makes the vitreous body visually recognizable.