Cancer cachexia is a multifactorial metabolic syndrome that affects ～50％-80％ of cancer patients,and no effective therapy for cancer cachexia is presently available.In traditional Chinese medicine,a large portion of patients with cancer cachexia was diagnosed as spleen deficiency syndrome and treated with tonifying TCMs that produce clinic benefits.In this study we established a new animal model of spleen deficiency and cancer cachexia in mice and evaluated the therapeutic effects of atractylenolide I,an active component of tonifying TCM BaiZhu,in the mouse model.Cancer cachexia was induced in male BALB/c mice by inoculation of mouse C26 colon adenocarcinoma cells,whereas spleen deficiency syndrome was induced by treating the mice with spleen deficiency-inducing factors,including limited feeding,fatigue,and purging.The mouse model was characterized by both cachexia and spleen deficiency characteristics,including significant body weight loss,cancer growth,muscle atrophy,fat lipolysis,spleen,and thymus atrophy as compared with healthy control mice,cancer cachexia mice,and spleen deficiency mice.Oral administration of atractylenolide I (20 mg· kg-1per day,for 30 days) significantly ameliorated the reduction in body weight and atrophy of muscle,fat,spleen,and thymus in mice with spleen deficiency and cachexia.The established model of spleen deficiency and cancer cachexia might be useful in the future for screening possible anticachexia TCMs and clarifying their mechanisms.