A vitreous body visualization agent which is to be injected into the eye to visualize the vitreous body by a safe and sure method. The vitreous body visualization agent is prepared by using a polymeric substance having positively or negatively charged functional groups and adding a hardly water-soluble and non-steroidal colored substance, in which the polymeric substance is to be suspended, thereto. Due to having a non-steroidal nature, it can be safely injected into the eye, and the colored substance, in which the polymeric substance is to be suspended, makes the vitreous body visually recognizable.