Abstract:Based on Dual Process Theory, this paper tries to investigate the differences on problem recognition, strategic decision, and translation quality in the controlled processing between student and professional translators from a problem-solving perspective.Cognitive data in the English-Chinese translation processes are collected by triangulating a variety of data sources such as TAPs, questionnaire, interviews, etc.The findings are as follows:1) Students' problem rate (problems per 100 words in the ST) was twice as high as that of the professionals.Differences between students and professionals were most salient in the combined and production problems.Combined problems often occured in dealing with contexts, rhetoric and semantic analysis, while production problems were related to the form, meaning and usage of target language.2) In the controlled processing, student translators employed retrieval strategies more frequently, while professionals preferred to use decision-making and monitoring strategies.3) The mean value of the total amount of student translators' errors was twice as high as that of the professionals, manifested particularly on the textual, grammatical, stylistic and lexical levels.This study is meaningful for exploring translators' mental activities and cultivating translation expertise.