The study tries to find the correlation between preferred reading strategies and language achievement of non-English majored students at two institutions at Thai Nguyen Universities; The International School and the Foreign Language Faculty. The participants are required to achieve IELTS 5.0-5.5 academic version for graduation. The study employs the Metacognitive Awareness of Reading Strategies Inventory, version 4.0 (MARSI) as a tool for data collection. The SPSS version 20.0 is used to analyze the data as well as to find out the preferred reading strategies of the students. The result of an IELTS which is adapted from Cambridge IELTS preparation 12 is used to compare the language achievement among different reading strategy users. The results of the study show that students use most reading strategies at moderate and high levels, except for GRS1, GRS2, GRS3 and PSRS3. The most preferred strategies include PSRS7, PSRS8, SRS1, SRS2, SRS6, SRS7, SRS9. The reading achievement is affected by GRS and PSRS. There is no significant different between the use of SRS and the reading achievement.