To provide a novel anti-psychosocial stress agent which is highly safety and can be continuously taken, more particularly, a novel anti-psychosocial stress agent which prevents or alleviates psychosocial stress.The invention provides an anti-psychosocial stress agent containing, as an active ingredient, uridylic acid, uridine, or uracil. Since uridylic acid, uridine, or uracil, which is an active ingredient of the anti-psychosocial stress agent of the present invention, is inexpensively available and is a biological component, the agent exhibits high safety and can be continuously taken. Therefore, the anti-psychosocial stress agent of the present invention is effective for mitigating, alleviating, or relieving psychosocial stress, which is an issue in modern society. When the anti-psychosocial stress agent is taken before development of symptoms associated with psychosocial stress, the symptoms can be prevented. The anti-stress effect of the agent is superior to that of GABA, which has become of interest and has been incorporated into, for example, foods.