Abstract :
In this competitive world, reading becomes an important skill for every human being, especially in the pursue to gain more knowledge. More and more people realize the importance of reading especially reading English books
because English occupies a special position for international language. However, reading English books is not easy for non-English speakers. That is why in Indonesia, students should learn more to improve their reading comprehension in order to broaden their mind by reading English books. The difficulties to comprehend English books can be caused by some factors. One
of those factors is the student's background knowledge.
When students should face a reading material that is unfamiliar to them, the tendency to comprehend becomes harder and this makes the students uninterested in reading the material. Conversely, students who face a familiar
reading material will be more interested and this will help them to comprehend more easily. This evidence leads the writer to investigate two problems: (I) Is there any correlation between familiar reading materials and the students' reading comprehension achievement? (2) Is there any correlation between unfamiliar reading materials and the students' reading comprehension achievement?
In conducting this research, the writer used the third year students of SMAK Dapena I Surabaya who belonged to the academic year of 1994/1995 as the subjects of the study. The data obtained from two kinds of reading material
tests -- familiar reading material tests and unfamiliar reading material tests -are then correlated using the Biserial Correlation. The result of this research shows that there is a significant correlation between familiar reading material and unfamiliar reading material and the
students reading comprehension achievement. In other words, if the students are familiar with the material, their reading comprehension achievement will be high.