We determined the stable carbon and nitrogen isotopic compositions (δ13C and δ15N) and nine trace element abundances (Mg, P, Ca, V, Mn, Zn, Rb, Sr, and Ba) of boiled and salted wakame (Undaria pinnatifida) from Sanriku, Naruto, South Korea and China, in order to evaluate their interannual variations between 2011 and 2012. The wakame from Naruto was characterized by relatively higher δ15N values than those from other areas in both years. There was no significant interannual variation of the δ13C and δ15N values. Based on a linear discriminant analysis using the δ13C and δ15N values of wakame collected in 2011, 93.0% of Naruko wakame could be distinguished from all others in 2012. Although the wakame from China had relatively higher abundances of Mg, V, Mn, Ba in both years, there were interannual variations in the abundances of Mg, V, P, Ca and Rb. Based on these δ13C and δ15N values and the trace-element abundances (Mg, V, Mn, Zn, and Ba) of wakame collected in 2011, we divided the wakame collected in 2012 into three groups: Naruto, China, and other areas (Sanriku and South Korea), with 98.2% and 83.3% discriminations being achieved for Naruto and China, respectively. The discrimination rate of wakame from China in 2012 decreased because of the interannual variation in the abundances of the trace elements. Thus, the interannual variation of the stable isotope and the trace-element compositions is needed to establish their database in order to discriminate the geographical origin of boiled and salted wakame.