This study examined Korean learners' production of intervocalic English biconsonantal clusters consisting of /p/, /t/, /k/, /m/, /n/, or /[eng] / followed by /l/ or /[voiced alveolar approximant]/. The results of the production experiment showed several factors influencing Korean learners' production. First, Korean learners' production was influenced by their L1 sound inventory. The mispronunciation of a liquid (i.e., /l/ as [[voiced alveolar approximant]] and /[voiced alveolar approximant] / as [l]) was observed and this will be due to the fact that [l] and [[voiced alveolar approximant]] are not contrastive in Korean. Second, L1 phonological rules affecting a post-consonantal onset liquid influenced Korean learners' production of English consonant clusters containing a liquid. The cluster /tl/ was mostly pronounced as [ll] and /nl/ as [ll] or [nn]. In addition, the nasalization of a stop consonant before a liquid was attested. Next, Korean learners' production also exhibited the influence of phonetic similarity between the two members of a cluster by illustrating relatively lower production accuracy for /tl/, /t[voiced alveolar approximant]/, and /nl/ consisting of two alveolar consonants. Finally, familiarity with the test words seemed to be a factor influencing Korean learners' production. Korean learners illustrated relatively lower production accuracy for the words "outlet" and "online" which are frequently used as loanwords in Korea.