Reading comprehension is a problem solving behavior that actively involves the reader in the process of deriving and assigning meaning. Individual readers employ different strategies while engaged in reading process, some being more efficient than others. Knowing what strategies students use in reading process, indeed, is very important to good reading teachers. 180 Vietnamese university non English majored students participated in the study. Three pre tests were given to the students to define successful and unsuccessful readers. The results of the study reveal that successful and unsuccessful readers showed great differences in their choice of cognitive strategies. The research also points out some factors affecting readers strategy use. They are gender, length of time of English learning and students interest in English learning. The study proposes the need to conduct a strategy training program for students, to conduct a more comprehensive strategy research on students types of strategies applied in reading and to get more information about the different ethnographic variables that may affect students choice of reading strategies in particular and in learning in general.