Objective In order to evaluate nursing students' clinical nursing knowledge and ability objectively, we tested a clinical nursing examination system which is based on the computer technology. Methods The proposed project used the whole group of sampling methods. Data were collected via class unit. All the 620 subjects recruited from seven classes of grade 2007 (280 students )and eight classes of grade 2008 (340 students). Results Students of grade two without clinical practice had lower scores when answering clinical nursing case problems compared with grade one students who went through clinical practice. Conclusions The computer simulated clinical nursing testing system has better validity and reliability in evaluating students' clinical nursing ability.