Food grade bioplastic has become a popular research topic these days. However, further studies are still required in order to develop bioplastic that has comparable mechanical and water barrier properties with synthetic plastic. In this research, to improve mechanical and water barrier properties of plant cellulose filled bioplastic, bacterial cellulose is added to create hybrid filler with banana pseudostem fibre in glycerol plasticized corn starch matrix. The filler banana pseudostem fibre and bacterial cellulose were first dispersed in mixture of glycerol and distilled water, starch was added and mixture was heated until gelatinization occured. The mixture was then casted and dried in oven. Research proved that 10wt% against starch mass was an optimum filler composition, which resulted in the highest mechanical strength of bioplastic. The utilization of hybrid filler showed a decrease in mechanical strength compared with bioplastic with single filler. The ratio of banana pseudostem:bacterial cellulose compotition in hybrid filler that gave the best mechanical properties was 25:75 which resulted in tensile strength 4.599 MPa and modulus 174.1 MPa. Although the utilization of hybrid filler did not improve the mechanical properties of bioplastic, the addition of bacterial cellulose was proven to give positive effect to water barrier properties. Bioplastic filled with hybrid 10wt% banana pseudostem fibre and 35wt% bacterial cellulose had water vapour transmission rate 3.8958 g/m2/hour. The mechanical and water barrier properties of bioplastic was confirmed with SEM, FTIR, and XRD analysis. Soil burial test for 9 days proved that banana pseudostem filler decreased 6.9% of corn starch bioplastic biodegradation rate.