Abstract: The multi-temporal leaf area index (LAI) data retrieved from remote sensing images have been widely used in climate simulation, crop growth monitoring and etc. However,there might be some missing data owing to temporal resolution, weather and some other factors. The support vector machine (SVM) is a kind of machine learning algorithm that has excellent properties. The least squares support vector machine (LS-SVM) algorithm is an improved algorithm of SVM. In this paper, the LS-SVM and SVM models were used to predict the LAI time series products of MODIS data of Naqu in year 2011, based on The multi-temporal leaf area index (LAI) data retrieved from remote sensing images have been widely used in climate simulation, crop growth monitoring and etc. However,there might be some missing data owing to temporal resolution, weather and some other factors. The support vector machine (SVM) is a kind of machine learning algorithm that has excellent properties. The least squares support vector machine (LS-SVM) algorithm is an improved algorithm of SVM. In this paper, the LS-SVM and SVM models were used to predict the LAI time series products of MODIS data of Naqu in year 2011, based on the MODIS LAI from 2003 to 2011. The results show that LS-SVM method performs better than SVM method. Therefore the predicted LAI data is proved to be very supportive for making up for the loss of remote sensing LAI time-series data, the LS-SVM method proposed in this study is significant to improve the quality of the LAI time series remote sensing products.