We sought to test a componential model of Chinese written spelling, including the role of orthographic working memory (OWM), among Hong Kong kindergartners. One hundred seventeen kindergartners were recruited. OWM was measured using a visual orthographic judgment and a delayed copying task. Orthographic knowledge, semantic knowledge, and visual-motor skills were assessed via a set of cognitive-linguistic measures. Model comparison yielded the best fitting measurement model, which consisted of four factors, namely, OWM, orthographic knowledge, semantic knowledge, and visual-motor skills. A structural equation model indicated that 79% of the variance in Chinese spelling could be explained by these four factors. OWM was the strongest correlate of Chinese written spelling. These results highlight the fact that OWM is a predominant and distinctive correlate of Chinese written spelling acquisition.