Taking the BMG series as a material system

the physi ca l and structural parameters of the BMG were separately calculated by the additio nal principle

including mixed entropy S mix

mole atomic radius differ ence εd

mole atomic electronic difference εe

thermal diffusion ratio α and ratio （T m/H m） of melting point temperature T m and me lting enthalpy H m. R c（critical cooling velocity）

Z max （ maximum size） and Z max /R c for BMG were considered as the targe t of glass forming abil ity respectively. The statistic figures ε d·ε e ·α·S mix ·T m/H m （denoted by Л）: R c

-Л

Z max -Л

Z max /R c-Л have been drawn by Origin 6.1 software. The re sults showed that the optimum GFA for Л=0.020～0.175

for Л=0.047～0.1 50 and for Л=0.03～0.15 when R c

Z max and Z max /R c as were taken as the target respectively. The range of c omprehensive optimum Л is 0.047～0.15. It was concuded that the Л was an ideal new paramete r to characterise the glass forming ability of the BMG.