This paper applies both the Engle-Granger and Johansen cointegration test procedures to determine the existence of market linkage among high-valued ( Scomberomorus commerson, milkfish ) and low-valued (cod, Taiwan Tilapia ) fish species using monthly average wholesale price data recorded on the Taipei fisheries wholesale market. If the markets for high-valued and low-valued species are linked, say through commodities arbitrage, individual fish prices cannot diverge ¡§too far¡¨ from other fish prices before market forces to operate to restore equilibrium. From the empirical results, it indicates the existence of only one cointegrating vector involving the prices of these species in Taipei fisheries wholesale market, and that a long-run and stable substitute relationship may exist for the Scomberomorus commerson and other low-valued and high-valued species.