The phonological acquisition of 129 monolingual Putonghua-speaking children, aged 1; 6 to 4; 6, is described. Putonghua (Modern Standard Chinese) syllables have four possible elements: tone, syllable-initial consonant, vowel, and syllable-final consonant. The children's errors suggested that Putonghua-speaking children mastered these elements in the following order: tones were acquired first; then syllable-final consonants and vowels; and syllable-initial consonants were acquired last. Phonetic acquisition of the 21 syllable-initial consonants was complete by 3; 6 for 75% of children. By 4; 6 the children were using the syllable-initial consonants correctly on two thirds of occasions (with the exception of four affricates). Simple vowels emerged early in development. However, triphthongs and diphthongs were prone to systematic errors. Tone errors were rare, perhaps because of their role in distinguishing lexical meaning. In contrast, acquisition of ‘weak stress’ and ‘rhotacized feature’ was incomplete in the oldest children assessed. Phonological processes used by the children were identified. Two of these processes, syllable-initial consonant deletion and backing, would be considered atypical error patterns in English. Existing theories of phonological acquisition (e.g. concepts of markedness, functional load, feature hierarchies) cannot account for some of the patterns revealed. A satisfactory explanation of the findings requires more attention to the specific characteristics of the linguistic system the children are learning. It is proposed that the saliency of the components in the language system determines the order of acquisition.