The purpose of this research is to investigate the effect of task-basedcollaborative learning (TBCL) on students’ achievement and affective domains,focused on the low level students of college English reading class. To thisend, the following three research questions were addressed: 1) How doesTBCL affect their academic achievement? 2) How does TBCL have an impacton their affective domains such as foreign language classroom anxiety,foreign language reading anxiety, motivation, and attitude? 3) What is acorrelation between their achievement and affective domains in TBCL?Participants were 101 college students mainly composed of freshmen(35 males,18 females in the experimental group; 30 males, 18 females in the controlgroup), who took 'English Reading 100' course in J university. In theexperiment group, TBCL was applied, while task-based whole class teachingmethod was utilized in the control group. To answer the three researchquestions, the pre-survey and the post-survey related to their backgroundand affective domains, the diagnostic evaluation, the post evaluation, and the post open ended questions were carried out. After that, the collected datawere quantitatively and qualitatively analyzed, using the statistic softwareSPSS 18 and the content analysis.The results of quantitative analysis showed that: 1) TBCL contributed toimproving their academic achievement in the experimental group. 2) TBCLpromoted the learners to feel less foreign language classroom anxiety andforeign language reading anxiety than before; and it helped them to developtheir more positive motivation and attitude than before. 3) only foreignlanguage classroom anxiety was correlated with their achievement within theexperiment group, except for the other affective domains: foreign languagereading anxiety, motivation, and attitude. In the control group, however, theirachievement was not correlated with any affective domains.It was also found in qualitative analysis that TBCL had more positiveimpact on the academic achievement and affective domains of the low levelstudents of college English reading class, rather than the task-based wholeclass teaching. For example, the students in the control group did complainthat they had little chance to make themselves understood in English andthat it was difficult to deal with the tasks alone. Those in the experimentalgroup, however, said that participating in TBCL activity enabled them tohave in a long term memory what they learned and devote themselves toleaning English and that it was because the class was interesting.