Abstract: Objective To observe the effect of bioimpedance analysis on residual renal function (RRF)in new hemodialysis patients with α-ketoacid supplemented low-protein diet by guiding hemodialysis combined with ultrafiltration. Methods A total of 160 patients with end-stage renal diseases newly undergoing hemodialysis in Jiangyin People's Hospital from January 2016 to October 2017 was selected and randomly divided into group A (α-ketoacid supplemented low-protein diet), group B(bioimpedance spectroscopy), group C (α-ketoacid supplemented low-protein diet and bioimpedance spectroscopy), group D(control group). The changes of RRF 6 months before and after treatment in each group were followed up. The patients in group A took α-ketoacid supplemented low-protein diet, and were guided for dialysis ultrafiltration volume based on heart-chest ratio, inter-dialysis body weight gain and inter-dialysis hypotension, dry mouth, and muscular convulsion. Bioimpedance spectroscopy was adopted to guide dialysis and ultrafiltration in group B, with normal protein diet. The patients in group C took α-ketoacid supplemented low-protein diet, and were guided for dialysis and ultrafiltration through bioimpedance spectroscopy. In group D normal protein diet was taken, and dialysis and ultrafiltration were guided in the same traditional way as group A. Twenty-four-hour urine volume, RRF, mean arterial pressure, hemodialysis and ultrafiltration volume and dial、ysis-related adverse event incidence before and after follow-up were compared in the four groups. Results The differences of 24-hour urine volume, RRF, mean arterial pressure and mean dialysis and ultrafiltration volume before and after follow-upwere statistically significant (P<0.001) in each of the 4 groups. However,comparison of serum albumin levels before and after follow-up showed no statistically significant difference in each of the 4 groups (P>0.05). After the follow-up of 6 months, RRF (mL/min) and 24-hour urine volume (mL) in each group exhibited a decreasing trend, with statistically significant differences (F_inter-group=5.530,F_intra-group=352.146,P<0.05, and F_inter-group=765 426.35,F_intra-group=59 645.256,P<0.001). RRF values(6.0±0.6)in group Chad the best protective action in the 4 groups, with significant difference(P<0.05), at a slow decreasing speed than those in other 3 groups; while RRF values in group A (4.6±0.5 mL/min), group B (4.8±0.6 mL/min) and group C(6.0±0.6 mL/min) had better protective action than group D (3.7±0.6 mL/min), with significant differences(P<0.05).The 24-hour urine volumes in group A(922.4±85.1 mL), group B (901.9±97.9 mL) and group C (1187.1±211.4 mL) were all higher than that in group D (653.2±74.2 mL),with statistically significant difference (P<0.05). In comparison of mean inter-dialysis ultrafiltration volume between the 4 groups, the differences were of statistical significance(F_inter-group=15.341,F_intra-group=32.625,P<0.001),wherein, the index values in group A (0.85±0.21 L), group C (0.60±0.25 L)were slower than those in group B(0.92±0.17 L) and group D (1.31±0.52 L) with statistically significant difference (P<0.05),and comparison between group B and D showed significant difference(P<0.05).In comparison of dialysis-related adverse events occurring during follow-up between the 4 groups, the differences were of statistical significance (χ²=3.771,P=0.013), with 6 cases in group A, 3 cases in group B, 1 case in group C and 8 cases in group D. Systolic blood pressure, diastolic blood pressure and albumin after follow-up between the 4 groups showed no differences of statistical significance (P>0.05).Conclusions On the basis of bioimpedance spectroscopy guided hemodialysis and ultrafiltration, the dialysis patients with α-ketoacid supplemented low-protein diet can maintain nutritional stastus,avoid hypoproteinemia,and accurately assess dialysis and ultrafiltration volume,which is conducive to delaying the decline of RRF,protecting RRF,and significantly reducing the incidence of adverse events during dialysis.