The Natural Forest Protection Project (NFPP) has been implemented since 1998 and completed by the end of 2020, which marked the transformation of China's forestry from wood production to ecological construction. Quantitative monitoring and assessing of natural forest resources is helpful to evaluate the effect of natural NFPP comprehensively, timely and scientifically. Based on the public land cover products, this paper uses new remote sensing data composition algorithm and the forest type comprehensive promotion method to produce a set of land cover products aiming at the forest coverage of the NFPP areas in China. The forest cover for NFPP is monitored and evaluated from 1997 to 2020. The classification accuracy of land cover products for NFPP is verified by the field data of the Chinese Forest Ecosystem Research Network (CFERN), forest inventory and planning data and ground survey data, which indicate the forest accuracies more than 90%. The results show that the forest coverage presents a general trend of recovery growth since the beginning of the NFPP. The forest coverage changes from 30.15% in 1997 to 31.74% in 2020, with a net increase of 1.59%, of which, the forest growth in the upper reaches of the Yangtze River is the highest, accounting for 50.97% of the total forest growth areas. The results show that the forest resources in the NFPP area are effectively protected and restored, and the implementation effect of the project is significant.