This study aimed to investigate the effects of oyster mushroom addition on the physicochemical properties of full fat soy (FFS)-based extruded meat analog. The meat analog blend was FFS, wheat gluten, and corn starch (0.5:0.4:0.1), and oyster mushroom was added to the base formulation (0, 4, 8, and 12%). The extrusion condition was set to 55% feed moisture, 170oC barrel temperature, and screw speed of 150 rpm by using the twin-screw extruder equipped with a cooling die. The hardness, chewiness, cutting strength, and integrity index of the FFSbased extruded meat analog increased with the increase in oyster mushroom contents, while its nitrogen solubility index (NSI) decreased. The cohesiveness, springiness, and water holding capacity revealed the inconstant patterns with the increase in oyster mushroom contents. The total phenolic content and DPPH radical scavenging activity significantly increased with the increase in oyster mushroom contents. In conclusion, the incorporation of the oyster mushroom into the FFS-based meat analog enhanced the textural properties and antioxidant activity.