Abstract: The study on the growth and mortality of Auxis thazard in the Taiwan Strait and its adjacent sea, mainly based on the vertebra material of the species to determine age. The relation formulae between fork and vertebra radius were: L= 3.5517+7.6183R, the longth-weight relationship formulas are calculated to be and, where W=2.505×10^-6L^3.3193 and W'=1.658×10^-6L^3.4065 represent net body weight (g) and total body weight (g) respectively. The parameters of fork length and net body weight growth equation are: L_∞=484.44mm, W_∞=2050.76g, k=0.5109, t=-0.3598. The turning point on body weight growth curve of the species was stuated at t= 1.4461 years of age. The instantaneous rate of total mortality is 1.1368, and the instantaneous natural and fishing mortality rates are 0.9040 and 0.2328 respectively. The rate of exploitation is 0.2048, the species be- long to the fish resource of lower exploitation.