A probe into the influence of global warming on the phenology and growth of Cunninghamia lanceolata seedlings was conducted in order to understand how C. lanceolata plantations may respond and adapt to the future climate in a humid subtropic area. In Fujian Normal University's Forest Ecosystem and Global Change Research Station in Chenda, Sanming, Fujian Province, a factorial air temperature manipulation (AT; ambient, open-top chamber)×soil temperature manipulation (ST; ambient, ambient+4℃) which included four treatments, i.e., control, air warming, soil warming, air and soil warming, was carried out. Air temperature manipulations were implemented by the open-top chamber method and soil temperature manipulations were implemented by soil cable heating. In 2016, 48 root boxes were built and each planted with one 1-year-old C. lanceolata seedling, to examine phenology and growth dynamics. The results showed that air temperature manipulations had significant effects on both shoot phenology and growth of the seedlings. Air warming significantly advanced the timing of apical bud swelling, apical bud break and apical bud new shoot growth, as well as significantly prolonged growing season length and promoted tree height growth. Soil temperature manipulation had no significant effect on either shoot phenology or growth of the seedlings. There were significant interactive effects of air and soil temperature manipulation on growth. Simultaneous air and soil warming promoted tree height and lateral branch growth more than individual warming treatments. We concluded that climate warming would benefit the growth of C. lanceolata plantations to some extent.