The statistical relaxation (SR) simulation has been conducted to study the behavior of simplexes and bubbles (BB) in amorphous Co metal containing 2×105 atoms. The simulation reveals that the fraction of 4-simplex increases and n-simplex (n>4) decreases depending upon relaxation degree. The simulation found that a large number of BB vary upon relaxation degree, which could play a role of diffusion vehicle for Co atoms in amorphous matrix. The idea of the diffusion mechanism in amorphous metal is described as follows: the elemental atomic movement includes a jump of neighboring atom into the BB and then a collective displacement of a large number of atoms around BB.