This study was directed to evaluate the dentin bond strength and color change of bulk fill resin composites with different incremental thickness using two curing modes. Extracted human molars teeth were used to prepare one hundred and twenty specimens. For shear bond strength, the specimens were divided into two main groups according to types of composite (Tetric N Ceram, Quixfil). Each main group was divided into two groups according to thickness of composite (2& 4 mm). Each group was divided into two sub-groups according to curing mode (Continuous and soft start mode). Then, each group was divided into three classes according to storage time (one day, three months, and six months). Fr color change, one hundred and twenty discs of resin composite were used in this study. The discs were divided into two main groups according to types of composites (Tetric N Ceram, Quixfil). Each main group was divided into two groups according to thickness of composite (2 mm, 4 mm). Each group was divided into two sub groups according to curing modes (Continuous and soft start mode). Then, each sub-group was divided into three classes according to immersions media (Acidic ph, alkaline ph solution. Neutral ph). Finally, each class was divided into three sub classes according to storage time (one day, three months, and six months). The shear bond strength was evaluated using universal testing machine at a crosshead speed of 0.5 mm/min until failure occurred. Data were recorded, tabulated and statistically analysed.The specimen's colors were measured using a Reflective spectrophotometer. The result showed the highest bond strength was recorded by (Quixfill, 4 mm, soft start at one day). For color change the (Quixfil, 4 mm, soft start, and acidic solution recorded the highest color change.