Objective: To investigate the effects of early oral fluid resuscitation on organ functions and survival in severe burn shock., Methods: Eighteen male Beagle dogs were surgically prepared for measurement, subjected to 50% total body surface area (TBSA) full-thickness flame injury 24 hours later, and then randomly divided into 3 equal groups: oral fluid resuscitation group (OR group) undergoing gastric infusion of glucose-electrolyte solution(GES)according to Parkland formula 0.5 hour after burn with the dose of 4 ml x kg(-1).%TBSA(-1), 1/2 being given in the first 8 h and 1/2 in the latter 16 h. Intravenous (IV) resuscitation of GES group (VR group) undergoing IV infusion of GES with the same dose as mentioned above, and no fluid resuscitation (NR) group given with GES during the first 24 h. In the second 24 hours all dogs received IV fluid resuscitation. At the end of 72-hours-period experiment, the mortality was recorded. The mean arterial pressure (MAP), plasma blood volume (PV), hematocrit (HCT), urinary output, alanine aminotransferase (ALT), creatinine (Cr), and MB isoenzyme of creatine kinase (CK-MB) were examined before injury and at 2, 4, 8, 24, 48 and 72 hours after injury., Results: At the end of 72-hours-period experiment, all dogs died in the NR group, 3 dogs died in the OR group, and no dog died in the VR group. The MAP and PV were significantly reduced after burn compared with those before-injury in the NR group, with the lowest levels of (34 +/- 9) mm Hg and (32.7 +/- 3.5) ml/kg (both P < 0.05) 8 h after burn, and the HCT, ALT, Cr, and CK-MB levels of the NR group peaked 8 h after burn to the levels of (61.7 +/- 2.7)%, (121.1 +/- 4.8) U/L, (91.0 +/- 6.1) micromol/L, and (13 891 +/- 297) U/L respectively. Eight hours after burn 4 dogs of the NR group showed anuria, and the rest two had the urine volume of 1.2 and 2.1 ml/kg respectively. Eight hours after burn the MAP, PV, and urinary output levels of the OR group were (84.3 +/- 17.1) mm Hg, (41.7 +/- 3.6) ml/kg, and (2.6 +/- 1.8) ml/kg respectively, all significantly higher than those of the NR group (all P < 0.05), but significantly lower than those of the VR group [(113.0 +/- 10.0) mm Hg, (50.3 +/- 5.2) ml/kg, and (7.0 +/- 1.9) ml/kg respectively, all P < 0.05]. The plasma ALT level of the OR group was (81.4 +/- 10.8) U/L, significantly lower than that of the NR group (P < 0.05), but significantly higher than that of the VR group [(66.3 +/- 7.6) U/L, P < 0.05]. The levels of plasma ALT at other time points, as well as the Cr and CK-MB levels at all time points of the OR group were all significantly higher than those of the VR group (all P < 0.05). The MAP, PV, HCT and urinary output levels of the two resuscitation groups returned to the pre-injury levels 72 h after burn, but the ALT, Cr, and CK-MB levels were still significantly higher than the pre-injury levels., Conclusions: Although oral resuscitation with GES is not as efficient as IV resuscitation in 50%TBSA burn, it still can maintain the MAP and PV, protect the organ functions and reduce the mortality comparing to no resuscitation. Oral resuscitation may be an ideal alternative way of IV resuscitation, especially in wars or other site of mass casualties.