We have cloned two novel mitogen-activated protein kinase (MAPK) genes CEK2 and CSK1 from Candida albicans strain SC5314. The heterozygous and homozygous cek 2 and csk 1 mutants were obtained by homologous recombination. The cek2 and csk1 null mutant strains CAJ3 and CAJ6 grew as wrinkled clonis on solid YPD medium. Expression of CEK2 gene in strain CAF3-1 repressed the filamentous growth of the strain weakly. Two-hybrid results showed Cek2 and Csk1 could not interact with Cph1 and Hst7 directly. Cek2 and Csk1 might cooperate with the filamentous transcriptional repressor Tup1.