This paper dealt with forest biodiversity of four provinces, Hunan, Jiangxi, Hubei, and Anhui, along the middle and lower Changjiang, focusing on the current biodiversity state and its potential crisis. Based on a diagnostic census, this forest flora embraces nearly 10000 species of higher plants, e.g. seed plants, pteridophytes, and bryophytes. The flora is significantly characteristic, namely,primitive, endemic, rare, and complicated. Unfortunately, the biodiversity on the levels of gene, species, and ecological system is more or less suffering fragmentation or damage, which may have negative effects on sustainable economic devolopment and enviroment protection. In addition, the authors proposed several conservation strategies for this forest biodiversity.