Speakers frequently reuse earlier encountered structures. A long-standing view in language production research is that this structural priming is driven by the persistence of abstract syntax, independent from unordered, conceptual representations. However, evidence has been building that non-syntactic information can also influence structural choice. Here we examined whether and how the syntactic priming of relative clause structures might interact with the priming of the conceptual category order of adjectives in noun phrase production. Study 1 found that speakers are more likely to produce relative clause structures (spotted bow that’s green) after having heard relative clause structures (striped lock that’s blue) as opposed to an alternative structure (striped blue lock), and they also tended to repeat the conceptual order of the prime, with more pattern-first orders after pattern-first primes than after color-first primes. Critically, we found larger syntactic priming when the conceptual order of the prime persisted more in the target and larger conceptual order priming when the syntactic structure of the prime persisted more in the target. Studies 2 and 3 found that conceptual category order priming can be enhanced by adjective overlap as well as noun overlap between prime and target, whereas syntactic priming can only be enhanced by noun overlap. These results supported the interactive priming account: Although the syntactic structure and the conceptual order are represented at different levels and hence can be activated independently, the link between them is also primed, which enhances priming at both levels.