This paper concerns the divisibility of comprehension subskills measured in L2 listening and reading tests. Motivated by the administration of the new Web-based English as a Second Language Placement Exam (WB-ESLPE) at UCLA, this study addresses the following research questions: first, to what extent do the WB-ESLPE listening and reading items measure different comprehension subskills? Second, to what extent can L2 listening and reading be considered similar or different, with regard to the divisibility of comprehension subskills? Employing a structural equation modeling (SEM) approach, the factor structures of 110 test takers' scores on the WB-ESLPE listening and reading items were examined with regard to three types of subskills, that is, "understanding main/topical ideas", "understanding supporting/specific details", and "making inferences". The results of the analyses indicated that the WB-ESLPE listening and reading items measure two or three kinds of subskills, and that while L2 listening and reading might share a common comprehension process, they may be distinct in the decoding processes involved due to the difference in mode of presentation. It is suggested that this divisibility of subskills in L2 comprehension tests might depend on the test takers' L2 proficiency as well as on the task characteristics of the test administered to them. (Contains 6 figures, 7 tables and 3 footnotes.)