This research aimed to investigate the use of picture books by preschool teachers to instruct environmental concepts and their influence on resource saving by children. The study adopted qualitative research as a method to investigate 11 children aged 5-6 years in Taiwan. In addition, we used "the environmental protector" as a main theme, and designed three sub-themes, which included the Impact of Human Activities on the Environment, the Rubbish Problem and Recycling, and Environmental Protection and Resource Saving. We used eight young children's picture books that were related to environmental education to carry out eight weeks of teaching. The result of the research discovered that children's environmental concepts had increased greatly following the activities. The children learned about different types of recovery and the recycling of reusable resources and the importance of recycling; children also understood how to reduce rubbish, and how to use less water, electricity, and paper, plus other eco-friendly behaviour. Children saved resources through their own actions; for instance, children used less water when washing their hands and brushing teeth and brought their own hankies to school. Moreover, children also used less drawing paper and turned off lights and televisions without being reminded to save electricity. However, the reuse of plastic bags was not improved.