This study investigates the relationship of mathematics anxiety and achievement in college mathematics for engineering major freshman students. An revised and modified 30-item version of the Mathematics Anxiety Scale(MAS) was completed by 176 university engineering students enrolled in introductory calculus courses offered by the department of mathematics. Correlational analysis indicated complex interaction patterns between mathematics anxiety and mathematics achievement, depending on the level of anxiety. The results from this study confirm the negative correlation between mathematics anxiety and mathematics achievement in college mathematics for engineering major student, and also those support the claim that the relationships between mathematics anxiety and achievement have non-linear patterns.