Bonylip barb is a fish of Indonesian origin lower in economic value than introduced fishes like catfish and Nile tilapia. The fish's added value may be improved by subjecting it to a process which is aimed to derive its protein hydrolysate. The purpose of this research was to determine the functional properties and proximate composition of bonylip barb protein hydrolysate flour. Bonylip barb protein hydrolysate flour was produced by, first, grinding of the bonylip fish, then by hydrolysis with 5% (w/w) papain at 55 ^oC at pH 7 for 6 hours, and by centrifugation at 5,000 rpm at 4 ^oC for 20 minutes, with the supernatant resulted being freeze-dried. The bonylip barb protein hydrolysate flour produced was observed for the functional properties, proximate composition, and amino acid profile. The research results show that the bonylip barb protein hydrolysate flour's scores for the functional properties of water absorption, oil absorption, emulsifying capacity, bulk density, and solubility in water were 3.1 mL/g, 1.94 mL/g, 23.60 %, 0.83 g/ml, and 78.2 %, respectively. The bonylip barb protein hydrolysate flour contained water, protein, fat, and ash at 8.75 %, 84.65 %, 1.02 %, and 4.80 %, respectively.