B Background: effective healing of bone defects in dentistry requires synthetic bone grafts that combine adequate mechanical strength with controlled degradability. β- tcp exhibits good osteoconductive properties but is inherently fragile, whereas sodium alginate provides structural stability. combining these materials in a composite scaffold is expected to yield a more balanced material, with the variation in the mixture ratio influences both compressive strength and degradation behavior. objectives: to evaluate the effect of varying β-tcp and sa mixing ratios on the characteristics of composite scaffolds, including compressive strength, degradation and solubility. methods: this study is a laboratory experimental research with a post-test only control group design. the groups include a negative control (pure sa scaffold) and three treatment groups of β-tcp+sa composite scaffolds with ratios of 70:30, 80:20, and 90:10. scaffold characterization was performed through compressive strength, degradation, and solubility tests. results: the β-tcp–sa composite scaffold with a 70:30 ratio exhibited the highest compressive strength, with a mean value of 1.62 mpa. increasing the β-tcp ratio tended to reduce compressive strength. degradation and solubility tests indicated that scaffolds with higher β-tcp content showed slower degradation and solubility rates. conclusions: β-tcp–sa composite scaffolds demonstrate potential as synthetic bone graft candidates, and variations in mixing ratios significantly influence compressive strength, degradation, and solubility characteristics.