Objective To investigate the value of platelet, serum sodium and serum creatinine levels in the prognosis of patients with liver failure. Methods The clinical data of 155 patients with liver failure were retrospectively analyzed, and the patients were divided into improvement survival group (87 cases) and deterioration died group (68 cases) according to the prognosis. The hospitalization time of every patient was divided into 4 roughly equal time period, and observed at 5 points of time:T1-T5. The levels and abnormal rates of platelet, serum sodium and serum creatinine were compared. Results The T3 - T5 serum creatinine levels in deterioration died group were significantly higher than those in improvement survival group: (102.14 ± 75.67) μmol/L vs. (78.21 ± 26.68) μmol/L, (116.45 ± 110.64)μmol/L vs. (78.77 ± 29.25) μmol/L, (161.43 ± 153.23) μmol/L vs. (76.40 ± 27.26) μmol/L, and the T1 - T5 serum sodium and platelet levels were significantly lower than those in improvement survival group:(135.05 ± 6.24) mmol/L vs. (137.52 ± 5.26) mmol/L, (137.01 ± 4.99) mmol/L vs. (139.00 ± 3.89) mmol/L, (134.80 ± 16.74) mmol/L vs. (139.15 ± 3.77) mmol/L, (134.40 ± 11.69) mmol/L vs. (138.30 ± 8.75) mmol/L, (133.30 ± 8.93) mmol/L vs. (139.01 ± 9.10) mmol/L, and (122.46 ± 72.59) × 109/L vs. (149.70 ± 71.70) ×109/L, (110.18 ± 65.10) × 109/L vs. (152.09 ± 82.79) ×109/L, (107.32 ± 70.49) ×109/L vs. (169.32 ± 100.65) ×109/L, (97.06 ± 58.15) ×109/L vs. (183.57 ± 112.68) ×109/L, (94.66 ± 57.00) × 109/L vs. (191.36 ± 118.64) ×109/L, and there were statistical differences (P<0.05). The abnormal rates of T3-T5 serum creatinine, T2 - T5 serum sodium and T1 - T5 platelet in deterioration died group were significantly higher than those in improvement survival group, the serum creatinine: 22.06%(15/68) vs. 6.90% (6/87), 27.49% (19/68) vs. 8.05% (7/87) and 42.65% (29/68) vs. 10.34% (9/87), the serum sodium: 32.35% (22/68) vs. 13.79% (12/87), 39.71% (27/68) vs. 14.94% (13/87), 48.53% (33/68) vs. 12.64%(11/87) and 60.29%(41/68) vs. 11.49%(10/87), the platelet:45.59%(31/68) vs. 21.84%(19/87), 55.88% (38/68) vs. 24.14% (21/87), 54.41% (37/68) vs. 25.29% (22/87), 55.88% (38/68) vs. 21.84%(19/87) and 61.76% (42/68) vs. 20.69% (18/87), and there were statistical differences (P<0.05). Abnormal rate of platelet was highest in each time point. Conclusions In the course of pathological changes in deterioration and dead patients, the platelet is the first and most easily affected compare with serum sodium and serum creatinine; the platelet may be a sensitive marker for predicting clinical outcome in patients with liver failure.