Objective. To analyze the rates and levels of substance abuse of suspected drug cases between 2011 and 2017 in four counties of central Taiwan. Method. Data were collected from the build-up laboratory drug identification system. Frequency and percentage of descriptive statistics by Microsoft Office Excel 2010 were used to demonstrate the charts and trends of positive rates by counties and years. Results.95.4% of the suspected drug cases were positive. The percentage in Level one drugs of high mortality and addiction were decreasing. In the other hand, level two and three drugs presented an upward trend. In addition, mixed-substances abuse has become more popular since 2012. Conclusion. There were slight differences in positive rates of suspected drug cases among four counties of central Taiwan. Moreover, mixed-substance abuse has becoming more popular.