Problem-Based Learning (PBL) is a constructivist learning with the potential to enhance students' science process skill. The implementation of PBL has revealed many advantages, however, a free exploration from a highly complex environment may result in a heavier workload of memory. Accordingly, practicum method can be used to overcome the shortcomings of PBL with the support of authentic assessment. This research aimed to investigate the effect of PBL through practicum supported by authentic assessment, PBL, and conventional learning on science process skills of Dayak and Malay students in Animal Physiology lectures. The research used a quasi-experimental research design with a pretest-posttest nonequivalent control group design with 3 x 2 factorial design. Data collection involved a science process skill test. The data were analyzed descriptively and inferentially with ANCOVA. Significant differences between groups were assessed with LSD test. The result showed that the learning model influenced students' science process skill. The PBL model implemented through a practicum and supported with authentic assessment was the most influential being significantly different to both PBM model and conventional learning. Ethnicity did not significantly affect the students' science process skill. There was no interaction between learning model and ethnicity toward students' science process skill.