Cross-language transfer happens in bilingual reading development. However, little is known about whether L1 affects L2 spelling development. In addition, longitudinal studies are needed to examine the L1-L2 relations developmentally from the beginning of literacy learning. We tested whether and which Chinese (L1) literacy-related skill(s) in kindergartners predicted their English (L2) spelling in the first and second grades. Notably, the associations of previous L1 spelling to later L2 spelling were also examined. Regression analyses showed that kindergarten Chinese phonological awareness predicted English spelling in the first and second grades. Cross-lagged modeling suggested that kindergarten Chinese spelling predicted first-grade English spelling. However, with other literacy-related skills statistically controlled, first-grade Chinese spelling was negatively associated with second-grade English spelling. This study highlights the complexity of cross-language transfer, especially in the early stages of literacy learning. In early bi-literacy learning, the cross-language transfer between Chinese and English may change dynamically.