Abstract : The aim of this thesis is to examine the constraints which play a role in phonological development. This study was carried out in the framework of Paidologos, a crosslinguistic project entitled "Cross-language investigation of phonological development", whose aim is to better understand the interactions between universal and language-specific trends during the acquisition of word-initial sequences of consonant-vowel (CVs) in two-year-old to five-year-old children. The languages studied here are French and Drehu. The first part aims at comparing the relative frequencies of several word-initial CV sequences in French and Drehu. The results indicate that some common phonemes in the two languages differ in their respective frequency. The aim of the second part was to collect productions of French- and Drehu-acquiring children aged 2 to 5 years. The task consisted in the repetition of words and non-words with differing frequencies in the two languages. The aim was to study whether French-acquiring children produce less error than Drehu-acquiring children on sequences that are frequent in French but rare in Drehu and reciprocally. The results indicate that the influence of the input language on phonological development is strong for the youngest children. The patterns of production and error profiles differ according to the linguistic group. The results suggest that the link between frequency in the ambient language and child production is not simply explained by a generally lower frequency of articulatory difficult consonants in all languages. The results of this thesis confirm the major role played by frequency patterns in the ambient language during phonological development.