Longitudinal predictors of writing composition in Chinese and English written by the same 153 Hong Kong nine-year-old children were tested, and their production errors within the English essays across ten categories, focusing on punctuation, spelling, and grammar, were compared to errors made by ninety American nine-year-olds writing on the same topic. The correlation between quality of the compositions in Chinese and English was.53. In stepwise regression analyses examining early predictors at ages between five and nine years, tasks of speed or fluency were consistently uniquely associated with Chinese writing composition; measures of English vocabulary knowledge, word reading, or both were consistently uniquely associated with English writing quality. Compared to the American children, Chinese children's writing reflected significantly higher proportions of errors in all grammatical categories but did not differ in punctuation or spelling. Findings underscore both similarities and differences in writing at different levels across languages.