The protection and development of coastal mangrove forests in Kien Thuy, Hai Phong has become an urgent solution to mitigate the negative impacts of natural disasters, respond to climate change, and improve the quality of life of the local residents. This research provides the initial results to assess the efficiency of the planning and conservation effort since 1986 on the coastal mangrove forest in Kien Thuy, Hai Phong. Our results show that the mangroves started growing in the period from 1986 to 1991 and the coverage is now 603 hectares with good forest quality and high density of vegetation. The change process about the area of this mangrove vegetation consists of 5 stages, closely dependent on the rate of exploitation, socio-economic development, and forest restoration of the authorities and local people.