The purposes of this study were to develop a theoretical-based, comprehension process assessment and to measure children's reading comprehension processes. This assessment was based on Hannon & Daneman's (2001) paradigm and Hannon & Frias' (2012) component processes tasks, including the memory measure, the inference measure, knowledge access and integration measure, and modified to two parts in order to assess 4th to 6th graders' reading comprehension processes. We reduced the difficulties and complexity of this comprehension measure for younger children. Four-hundred-and-fifty participants (at 4th to 6th grade level) were recruited from four elementary schools in Chia-Yi, Taiwan. The results show that the Cronbach's alpha coefficients were .75 to .87 and the citerion-reference validity was around .70 to .75 with the Chinese Reading Comprehension Test. There were good item discriminations and difficulties, analysed by the Rash model.