The present invention provides a hydrogen absorption alloy, which includes chemical composition represented by the general formula M1tM2uM3vCawMgxNiyM4z wherein 16×(d−1.870) / (d−r)≦v≦16×(d−1.860) / (d−r); 1.6≦w≦3.2; 4.1≦×≦5.1; 3.2≦(y+z) / (t+u+v+w+x)≦3.4; t +u+v+w+x+y+z=100; M1 is one or more elements selected from La, Pr, and Nd; M2 is one or more elements selected from V, Nb, Ta, Ti, Zr, and Hf; M3 is one or more elements selected from Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu; M4 is one or more elements selected from Co, Mn, Al, Cu, Fe, Cr, and Zn; d is an average atomic radius of the elements selected as M1; and r is an average atomic radius of the elements selected as M3; and an electrode and a secondary battery using the same.