Previous research on blended learning (BL) implementation in L2 instructional settings considers L2 teachers' use of the incorporated CALL modes and learners' attitudes toward the CALL modes as critical factors, among other factors, for achieving successful BL implementation. In the literature, these two factors are suggested to be strongly associated. Although these findings have laid the foundation for us to see what happens in the process of BL implementation, few studies have examined the relationship between the two factors while simultaneously considering other factors which potentially influence learners' attitudes toward the incorporated CALL modes. Given the multidimensional aspects of BL implementation, the relationship between the two cardinal factors and their interrelation with other factors involved in BL implementation needs to be further examined. The present study addresses this gap in the literature. It examines the relationship between 244 Korean EFL students' attitudes toward the incorporated CALL modes under BL and the teachers' use of the CALL modes while taking into account students' other characteristics, such as computer literacy skills, gender, age, time spent on internet surfing and devoted to English study online, and prior BL experience. (Contains 3 tables, 1 figure and 8 notes.)