Global shark populations are seriously declining and many species are now threatened by anthropogenic stresses. Their extinction would cause devastating consequences to the marine biodiversity and ecosystems. However some children describe the sharks as bad guys, "we should kill them all!" Such children's view motivates my study interest. This research aims to investigate the children's perceptual belief and conceptual understanding of sharks and its ecological significance; and the associated variables affecting the results. The study has investigated a total of 140 school pupils of primary 4 level from 2 different schools. The results are presented in five-point Likert scores. The mean perceptual and conceptual scores are 3.26 and 3.53, respectively. No correlation is found between the overall conceptual score and the variables of gender, age or schools. Yet the conceptual score is positively correlated to the perceptual score, whereas the conceptual score is correlated to their examination result of the subject General Studies. Information acquired from the parental source shows the positive correlation to the overall conceptual scores whereas the effect is particularly significant to boys. However the reading preference of the nature type shows the positive correlation to the overall conceptual scores whereas the effect is significant to girls. It is also noted that the children spending longer time on reading score higher, yet the book types of computer information or games are negatively associated with the performance of boys in particular conceptual items. The results suggest three approaches for promoting the children's perceptual and conceptual development about the environmental issues: consolidation of the ecological knowledge backgrounds, identification of constructive information sources and the development of effective pedagogical strategy. (Contains 3 figures and 5 tables.)