In this study, the researcher examined the relationship between length of learning and the perception of Chinese tones by twenty-six American university students (aged from 18 to 42) who learned Chinese as a foreign language. The participants were first asked to complete a language background questionnaire, followed by receiving a Chinese tone identification test. Afterwards, Pearson Product-Moment Correlation Coefficients were conducted to analyze the collected data. The results of this study did not show any significant positive correlations between length of learning and the participants’ test scores for the Chinese tones. These research findings did not support the idea that the longer language learners learn a foreign language, the more accurately they can perceive the phonology of the language.