Research has shown that teaching science with a modeling-oriented approach, particularly with interactive simulations, will promote student engagement and understanding. To date, many interactive simulations have been developed and adopted for classroom practices. The purpose of this study was to explore secondary school science teachers' perceived affordance of interactive simulation as well as their practical experience with simulation implementation in class. Twelve science teachers from seven schools were interviewed individually and the data was triangulated with their teaching plans and student assignments. Their past experiences of simulation implementation revealed that most teachers adopted simulations for demonstration purpose in teacher-led instruction. Their attempts to provide students opportunities to use the simulations to explore alternative modeling by themselves did not seem to work well. There are various reasons for this, such as the shortage of facilities, Internet bandwidth, and technological knowledge. There was also a pressing need for teachers to complete the required syllabus in limited classroom time. The majority of teachers' future intent to use simulation in class was quite weak, especially with the less proficient students who had some difficulty understanding simulations. Although interactive simulations have great potential to promote students' understanding in abstract science concepts, overcoming the difficulties of implementation may require other alternatives such as a flipped classroom approach. Future studies can investigate how to design learning activities outside class, to engage students in exploring modeling in simulations.