First　principles　calculation　for　the　energies　and　magnetic　moments　of　Fe2CrAl　with　various　structures　has　been　carried　out.　The　contradiction　between　theoretical　and　experimental　magnetic　moment　of　Fe2CrAl　has　been　illustrated.　The　L2(1)-based　structure　has　the　lowest　energy　and　thus　should　be　formed　during　synthesis,　while　the　native　magnetic　Cr-clusters　are　responsible　for　the　extra　large　magnetic　moment.　Based　on　these　calculations,　a　metastable　and　partially　disordered　B2(CD)　structure　has　been　achieved　in　a　ball-milled　Fe2CrAl　alloy.　It　shows　a　300　K　higher　T-C　and　a　1.5　mu　B　higher　M-S,　respectively,　compared　with　the　arc-melted　samples　with　L2(1)-based　structures.