Stuttering is a common neurological deficit and its underlying cognitive mechanisms are a matter of debate,with evidence suggesting abnormal modulation between speech encoding and other cognitive components.Previous studies have mainly used single task experiments to investigate the disturbance of language production.It is unclear whether there is abnormal interaction between the three language tasks (orthographic,phonological and semantic judgment) in stuttering patients.This study used dual tasks and manipulated the stimulus onset asynchrony (SOA) between tasks 1 and 2 and the nature of the second task,including orthographic,phonological,and semantic judgments.The results showed that the performance records of orthographic judgment,phonological judgment,and semantic judgment were significantly reduced between the patient and control groups with short SOA (P < 0.05).However,different patterns of interaction between task 2 and SOA were observed across subject groups: subjects with stuttering were more strongly modulated by SOA when the second task was semantic judgment or phonological judgment (P < 0.05),but not in the orthographic judgment experiment (P > 0.05).These results indicated that the interaction mechanism between semantic processing and phonological encoding might be an underlying cause for stuttering. Stuttering is a common neurological deficit and its underlying cognitive mechanisms are a matter of debate, with evidence suggesting abnormal modulation between speech encoding and other cognitive components. Previous Studies have mainly used single task experiments to investigate the disturbance of language production. It is unclear whether there is abnormal interaction between the three language tasks (orthographic, phonological and semantic judgment) in stuttering patients. This study used dual tasks and manipulated the stimulus onset asynchrony (SOA) between tasks 1 and 2 and the nature of the second task, including orthographic , phonological, and semantic judgments. The results showed that the performance records of orthographic judgment, phonological judgment, and semantic judgment were significantly reduced between the patient and control groups with short SOA (P <0.05) .However, different patterns of interaction between task 2 and SOA were observed across subject groups: subjects with stut tering were more strongly modulated by SOA when the second task was semantic judgment or phonological judgment (P <0.05), but not in the orthographic judgment experiment (P> 0.05). These results indicated that the interaction mechanism between semantic processing and phonological encoding might be an underlying cause for stuttering.