The invention relates to an imaging agent, and in particular relates to an imaging agent for gastrointestinal B-ultrasonic examination. The imaging agent is prepared from the following raw materials: 20 grams of largehead atractylodes rhizome, 15 grams of cyperus rotundus, 20 grams of officinal magnolia bark, 20 grams of tangerine peel, 20 grams of white paeony root, 10 grams of medicated leaven, 10 grams of cinnamon bark, 10 grams of orange Jessamine, 10 grams of shinyleaf pricklyash root, 6 grams of bitter orange, 8 grams of Chinese thorowax root, 10 grams of medicinal evodia fruit, 10 grams of yam, 5 grams of liquid paraffin, 2 grams of fatty methyl ester ethoxylate, 2 grams of tween 80, 1 gram of didecyldimethylammonium chloride, 5 grams of glycerin and 1 gram of allantoin. The imaging agent has the effects of promoting the circulation of qi for deswelling and regulating qi-flowing for harmonizing stomach, bubbles in stomach and intestines are rapidly removed, gastrointestinal motility is promoted, gastrointestinal mucus is eliminated, echo dark areas in gastral cavity are eliminated, the interference of acoustic impedance to gastrointestinal B-ultrasonic diagnosis is eliminated, the definition of gastrointestinal B-ultrasonic examination is improved, the structure of each layer of gastric walls is definite, lesions are highlighted, and the probabilities of missed diagnosis and misdiagnosis are reduced.