This study aimed to investigate the compatibility of developed mathematics textbooks' content (grades 6-8) in Saudi Arabia with NCTM standards in the areas of: number and operations, algebra, geometry, measurement, data analysis and probability. To achieve that goal, a list of (NCTM) standards for grades (6-8) were translated to Arabic language, and a content analysis card was developed in the light of standards list for mathematics textbooks for the academic year 1434-1435 AH / 2013-2014 AD. The study results revealed that the content of developed mathematics textbooks for grades (6-8) is compatible with 96.3% with NCTM standards, since the content anticipate 52 expectations from the standards list, while 3.7% from the NCTM standards expectations list were not achieved in the mentioned five areas.