Abstract：Abstract: The present study aimed to investigate how the complexity, accuracy of oral language develops over time in a group of ten college Chinese-speaking learners of English within the framework of Complex Dynamic System Theory (CDST), and made a first attempt to look into the relationship between complexity and accuracy by adopting CDST-approaches (moving min-max graph, moving correlation,). The result of our analysis shows that, firstly, complexity and accuracy of the oral language of learners indeed increase over time; at the group level the general development trend of complexity and accuracy is fairly linear but at the individual level is non-linear with a high degree of variability; individual learners follow different developmental paths. Secondly, a complex interplay between complexity and accuracy, and the relationship between them changes from a clearly competitive relation during the early stages to a supportive relation at later stages. This changing direction of the relationship shows that the complexity goes hand in hand with accuracy, which corroborates the interconnectness of subsystems as one of the major characteristics of CDST. Research findings may have some implications for oral English teaching in China.
Key words: Complex Dynamic System Theory (CDST); second spoken language; complexity; accuracy
