Twenty-seven children, with typical language development (TLD), 8-10 years old and 10-12 years old, were assessed with keystroke-logging in order to investigate their narrative writing. Measures of the writing process and the written product were used. One purpose was to explore how children produce written narratives in on-line production, and to relate the writing process to the written product. The results showed that those children who produced the final text faster, also wrote stories that comprised of more words. In the group of older children, children with better narrative ability used less pause time than those with worse ability, and the girls were faster writers than the boys. We believe that keystroke-logging gives valuable information for the assessment of young children's writing and that it is a potentially valid assessment tool for children from about 10 years of age.