The objectives of this study are to monitor the status of crab pot fishery resources and production economic in the northern waters off Taiwan. In this study, 11 sample vessel data and 600 three-spotted swimming crabs ( Portunus sanguinolentus ) were collected to be analyzed. The results indicated that highest value of CPUE, IPUE, landing, and value were October, 2016 and had a peak during August, 2016 to January, 2017. Thus we assumed that the major fishing seasons of crab pot fishery are during autumn to winter. Regarding to species composition of fishing harvest, the top three species were 96.41% of the total landing, including Crucifix crab ( Charybdis feriata ), Three-spotted swimming crab, and ridged swimming crab ( Charybdis natator ). The crab pot fishing vessels operated full year in the northern waters off Taiwan. In spring and summer, some fishing vessels moved to offshore waters of Taichung, Changhua, and Penghu. The results of monthly profit rate (PR) showed that the monthly PRs were higher than other months during September to December, 2016. In this period, the monthly PR reached 34.5% and above.