Abstract: With statistics and its principal component analysis (PCA), the evaluation of examination scores of hydrology and hydrogeology course and its five question types shows that the overall results are good. The average results of each question type show the scores for explanation of noun and blank filling are higher, while the scores for comprehensive questions, multiple choice and short answer questions are relatively low. Two-dimensional diagram of PCA shows that short answer questions and comprehensive questions are highly related to first shaft, which are the main factors influencing students' performances; on the other hand, blank filling and multiple choice are highly related to second shaft, which are of secondary causes.