Estimation of leaf area index (LAI) time series is a hotspot in remote sensing, because it allows tracking of vegetation biomass changes over a growth period. In this study, we acquired multi-temporal HJ-CDD remote sensing images of an aspen forest in Chuzhou area and synchronously measured LAI using LAI-2000. LAI estimation models of different growth stages (leaf production, flowering, fruit bearing, leaf constant period, and leaf abscission period) were constructed using normalized difference vegetation index (NDVI). Contrastive analysis was used to obtain LAI estimation model of the aspen forest over a growth period and estimated LAI was verified. The results showed that the model could be applied to estimate LAI over a growth period and provide useful information on the dynamic monitoring change of LAI.