Cellulase enzymes have an important role in biocatalyst technology, especially in the pulp industry. Cellulase is synthesized by a large type of microorganisms, including cellulose-producing bacteria isolated from Kemiri Sunan (Reutealis trisperma) shell and empty fruit bunches of the palm oil (EFBPO). In this study, the screening of cellulase-producing bacteria isolated from Kemiri Sunan shell and EFBPO were carried out in order to evaluate its enzyme activity. The method used was an experimental method followed by descriptive analysis using four treatments with two repetitions. This study includes; (1) Lignocellulosic biomass analysis, (2) Isolation of cellulase-producing bacteria, (3) Qualitative assay of cellulase-producing bacteria, (4) Enzyme activity assay. Both cellulose and hemicellulose contents in Kemiri Sunan shell were 27.38% and 44.46%, respectively, and 48.55% and 28.06% in empty fruit bunches of palm oil. Qualitative assay of cellulase-producing bacteria from Kemiri Sunan shell resulted in the widest clear zone accounting of 77.19% (isolate K2) and 73.06% (isolate T3) from EFBPO. Screening continued by measuring the cell growth with an interval time of 8, 24, 32 and 48 h. The enzyme activity showed the highest cellulase activity (isolate K3) from Kemiri Sunan shell was 4.3 í— 10-2 U/mL after 48 h incubation. However, isolate T4 from EFBPO resulted in higher cellulase activity than that Kemiri Sunan shell, accounting of 7.2 í— 10-2 U/mL. Our study suggests that cellulase-producing bacteria from Kemiri Sunan and EFBPO has been screened to synthesize cellulase enzyme.