A cobalt(ii) compound [Co(C14-terpy)(2)](BF(4))(2).MeOH (1) with long alkyl chains was prepared, and exhibited unique SCO at T(1) = 50 K and spin transition at T(2) upward arrow = 206 K and T(2) downward arrow = 184 K with hysteresis (DeltaT = 22 K) accompanying the motion of the long alkyl chains.