According to Kintsch and van Dijk’s (1978) theoretical model, we investigated the summarization processes of children with different ages. By manipulating three versions of texts, this study measured the process of reading comprehension and investigated the relationship between reading ability and summarization for Chinese readers. Participants were 34 third graders and 34 sixth grades. They were asked to read three different versions of texts and then performed three cognitive tasks (free recall, summarization, textbase questions). The results showed that there were moderate correlations among the measures of summarization, free recall and text comprehension, but no correlations among the measures of deletion, generalization and construction processes. Sixth graders outperformed third graders on all cognitive tasks. Readers at different developmental stages exhibited a significant difference in the sub-process of children’s summarization skills. The performance on the deletion-version was better than that on the generalization-version and construction-version. Among them, the performance on construction-version was the worst. Only one-fifth of third graders and one-third of sixth graders could select topic sentences of the text correctly.