The evaluation of compressive strength of cement-spent resins matrix mixed with biochar was investigated. In this study, biochar with different percentage (5%, 8%, 11% 14% and 18%) was used as alternative admixture material for cement solidification of spent resins. Some properties of the physical and chemical of spent resins and biochar were also investigated. The performance of cemented spent resins with the addition of biochar was evaluated based on their compressive strength and the water resistance test. The compressive strength was evaluated at three different curing periods of 7, 14 and 28 days, while 4 weeks of immersion in distilled water was chosen for water resistance test. The result indicated that the compressive strength at 7, 14 and 28 days of curing periods were above the minimum criterion i.e. > 3.45 MPa of acceptable level for cemented waste form. Statistical analysis showed that there was no significant relationship between the compressive strength of the specimen and the percentage of biochar content. Result from the water resistance test showed that only one specimen that contained of 5% of biochar failed the water resistance test due to the high of spent resins/biochar ratio. The compressive strength of cement solidified spent resins was found increased after the water resistance test indicating further hydration occurred after immersed in water. The results of this study also suggest that the specimen with 8%, 11%, 14% and 18% of biochar content were resistance in water and suitable for the leaching study of radionuclides from cement-biochar-spent resins matrix.