Abstract: This paper reported the relationship between the levels of urine FDP and lysozyme and the clinical state in burn patients. The patients were devided into 4 groups according to their burn surface, i. e. group A （burn surface less than 10%）, group B （11-30%）, group C （31-50%,） and group D （51-96%）. The levels of urine FDP and lysozyme gradually increased, in proportion to the severities of the burn, for example the levels keeping in normal range in group A but increased markedly in group C or D （1.65 or 3.5ug/ml and 30.5 or 99.24 ug/ml respectively）. Another interesting phenomenon is that the prognosis of burn patients was very poor when the levels of FDP or lysozyme reached to 4.99 ug/ml or 91 ug/ml respectively. Urine FDP and lysozyme detection seems to be of value in estimating the severity of burn and predicting the renal functions and the presence of septesis following burn injury.