A fundus image processing apparatus that processes a fundus image of an examinee's eye, the fundus image processing apparatus includes: a processor; and a memory storing computer readable instructions, when executed by the processor, causing the fundus image processing apparatus to: identify the optic disc included in the fundus image; identify a blood vessel included in the fundus image; calculate an upper diameter ratio which is a diameter ratio of those of the identified blood vessels that are positioned in a region above a height of the optic disc; calculate a lower diameter ratio which is a diameter ratio of those of the identified blood vessels that are positioned in a region under the height of the optic disc; and calculate an arteriovenous diameter ratio in the fundus of the examinee's eye based on the upper diameter ratio and the lower diameter ratio.