Based　on　the　fundamental　thermodynamic　principles,　the　ordering　behavior　of　the　ThMn12-type　intermetallics　NdFe10-xCoxMo2　were　studied　using　a　general　four-sublattice　model　supported　with　first-principles　calculations.　The　results　show　that　the　2a　sublattices　are　occupied　by　the　rare　earth　elements　Nd　exclusively,　while　the　50%　of　8i　sublattices　are　occupied　by　Mo　atoms,　8f,　8j　and　the　rest　50%　of　8i　sublattices　are　shared　by　Fe　and　Co　atoms,　which　agreed　well　with　the　reported　experimental　results.　Site　occupancy　fractions　of　Fe　and　Co　atoms　vary　with　temperature　in　the　quaternary　alloys　due　to　the　partial　solid　solution　of　Fe　and　Co　atoms　in　sublattice　8f　and　8j,　while　they　keep　constant　in　ternary　alloys　upon　varying　temperature.　Co　and　Fe　atoms　can　substitute　each　other　without　affecting　the　ordering　behavior　of　the　intermetallics.　In　the　alloy　NdFe5Co5Mo2,　with　an　equal　the　content　of　Fe　and　Co,　Fe　atoms　favor　the　occupancy　of　sublattice　8f,　while　Co　atoms　prefer　the　occupancy　of　sublattice　8j.