This study surveyed the spatial and temporal distribution of Temora turbinata in the waters of the Tanshui River estuary. The sea surface temperature and salinity ranged from 17.6 to 28.9 ℃ (highest in summer and lowest in winter) and from 32.2 to 34.4 psu (highest in spring and lowest in summer), respectively. The sea surface temperature and salinity ranges in the spring and summer of 2012, an El Niño year, were different than they were during the same seasons in 2010 and 2011. These results suggested that increasing rainfall and the introduction of water from the Taiwan Strait caused the temperature and salinity to increase in the spring of 2012. T. turbinata were distributed throughout all sampling stations checked during the study period, with the abundance varying from 0.1-89563 ind./m3, and blooms occurring in the summer (262-6768 ind./m3) of each year and in the spring of 2012 (7530.7 ind./m3). The optimal temperature and salinity ranged from 24.9 to 28.7 ℃ and from 32.7 to 33.5 psu, respectively. Two causes for the T. turbinata blooming seasons were identified: (1) the higher temperatures in the spring and summer were advantageous to the proliferation of local T. turbinata and (2) recruitment from the Taiwan Strait current.