OBJECTIVES: For early diagnosis, colorectal cancer screening (Fecal Immunochemical Testing) has been promoted and implemented on a large scale by Health Promotion Administration in Taiwan since 2010. Besides, targeted therapies (bevacizumab, cetuximab, panitumumab, regorafenib) have gradually become available for better treatment since 2005. This study aims to explore the effects of large-scale colorectal cancer screening on incidence and diagnosis of colorectal cancer in Taiwan overtime. We also examined the influences of availability of targeted therapies on clinical outcomes of colorectal cancer overtime. METHODS: Using an interrupted time series design and segmented regression, we estimated changes in age-standardized incidence rate, proportion of early/late diagnostic stage, five-year survival rates and age-standardized mortality rate of colorectal cancer following the above interventions. RESULTS:  After the large-scale colorectal cancer screening in 2010, the incidence rate of colorectal cancer increased suddenly but decreased later on. There was a relative decrease of 1.85% in incidence rate at 3 years following the screening. Proportion of early diagnostic stage did not significantly increase as expected, while proportion of late diagnostic stage substantially reduced 15.32% (C.I.: -21.69%, -8.96%) at 3 years after the screening. Following the first targeted therapy (bevacizumab) became available in 2005, the five-year survival rate relatively increased 6.49% (C.I.: 4.59%, 8.39%), however, mortality rate also increased 8.79% (C.I.: 2.28%, 15.30%) at 3 years after the use of targeted therapies. CONCLUSIONS:  The study found that the implementation of large-scale colorectal cancer screening was helpful to decrease the proportion of late diagnostic stage, no significant increasing of proportion of early diagnostic stage was found though. Despite targeted therapies were beneficial for increasing survival rate, the overall mortality did not reduce. Better use of targeted therapies is needed to be considered in Taiwan.