Abstract: In recent 20 years, researchers have began to learn that mental arithmetic is influenced by mathematics anxiety. The meaning and measurement of mathematics anxiety were introduced in the paper. Mathematics anxiety effect is related to problem-size effect. It is not significant when mental arithmetic problems are simple, but it becomes more significant with the difficulty growing. Moreover, the procedures of code, retrieve and selecting strategy are influenced by mathematics anxiety. Current research was apt to verify the processing efficiency theory, but inhibition theory was also an alternative, which is lacking in evidence

Key words: mathematics anxiety, mental arithmetic, processing efficiency theory, inhibition theory