We investigated the time course of property- and relation-based conceptual combination by showing asymmetric activa-tions of intrinsic and extrinsic semantic features in the two different combination types. Participants made lexical decisionson modifier or head associates at two different time points followed by sensicality judgments on noun-noun compoundsconstructed to facilitate either property- or relation-based interpretations. For property-based compounds, lexical deci-sions on modifier associates (intrinsic features) were facilitated, whereas those on head associates were inhibited. Forrelation-based compounds, however, lexical decisions on head associates (extrinsic features) and modifier associates wereequally facilitated. These asymmetric activations of intrinsic and extrinsic semantic features appeared only when the com-binatorial processes were completed. Our findings suggest that combinatorial processes can be considered as facilitationand inhibition of specific semantic features to form new concepts.