While Chinese language learning in Australian schools is characterised by predominantly second language programs for learners who have had no prior exposure to the target language, there is increasing participation by Australian-born children who speak Putonghua (Mandarin) or another dialect at home. Curriculum and assessment frameworks and syllabuses at senior secondary level have responded to the diversity in learner background through the provision of separate curricula and assessment schemes for different learner groups based on country of birth, prior educational experience and languages used at home. However the impact of learner background on learning and achievement as learners progress through Chinese language programs both in primary and secondary school remains under-researched. In particular, evidence of how the performance of second language learners differs from that of learners who a) speak the language at home and b) may have substantial community schooling experience beyond the school classroom, or c) were born and initially educated in Chinese, is very limited. This paper reports on the results of the Student Achievement in Asian Languages Education (SAALE) Project (Scarino et al., 2011; Scarino, this issue and Elder, Kim & Knoch, this issue) with regard to student achievement in Chinese. It focuses on the writing performance of Year 10 learners of Chinese and considers specifically the impact of language background by comparing performances between Australian-born students who do and do not speak Chinese at home. Scores assigned to students' writing gathered on common test procedures confirms the expectation that background language learners perform at significantly higher levels and suggests that the two groups also differ in the nature of that performance. The implications of this data for the teaching, learning and assessment of Chinese in schools, and for the appropriate provision of programs for these different groups of learners is discussed. (Contains 2 tables.)