Abstract： Objective To analyze the clinical characteristics of chylous effusion and boost its diagnostic and therapeutic level. Methods A retrospective analysis was conducted for 123 cases of chylous effusion at our hospital between January 1990 and December 2009. Results The main clinical manifestations of chylous effusion included dyspnea ( 55.3% ), edema ( 26. 8% ), abdominal distention (22. 8% ) and loss of weight ( 17. 1% ). Hypoalbuminia was common (45. 5% ) and it was even more so in patients with idiopathic lymphopathies or of unknown causes (95.2%). The positive rates of identifying chylous effusion by Sudan Ⅲ test, high triglyceride levels ( ＞ 1.25 mmol/L), lymphangiography or lyphangioscintigraphy were 89. 1%, 80. 6%, 70. 6% and 89. 5% respectively. Its common etiologies included injury ( 14. 6% ), malignancy (9. 0% ), infections ( 7.3% ), lymphatic disorders or idiopathic lymphopathies ( 40% ), drug-associated ( 2. 4% ) or associated with underlying disorders ( 16. 3% ).Efficacy was achieved in 63.6% of the patients and 21.8% died. Conclusions Chylous effusion is a special type of serous effusion with multiple causes. Its clinical manifestations are often nonspecific. But malnutrition is common. Its causes are identified after a systematic evaluation. Treatment modalities include dietary modification, management of underlying causes and surgical approaches.