Purpose: Cochlear implants (CIs) provide significant benefits for profoundly deaf children in their language and cognitive development. However, it remains unclear whether Mandarin-speaking young children with early implantation can develop age-equivalent phonological awareness (PA) skill and working memory (WM) capacity as their normal hearing (NH) peers. The aim of this study was to investigate PA and WM in preschool-aged children with or without hearing loss and to examine the relationship between the two basic skills. Method: The data were collected from 16 Mandarin-speaking preschoolers with CIs and 16 age-matched children with NH. All preschool participants were instructed to complete four phonological detection tasks and four digit span tasks. Linear mixed-effects modeling was performed to evaluate PA and WM performances between two groups across different tasks. Results: CI preschoolers showed comparable performances on par with NH controls in phonological detections and visual digit spans. In addition, Pearson correlation analysis revealed a positive relationship between phonological detections and auditory digit spans in preschool-aged children with CIs. Conclusion: With early implantation, the congenitally deaf children were capable of developing age-appropriate PA skill and WM capacity, which have practical implications for aural rehabilitation in this special pediatric population.