Abstract: In 1957, Dr. Zhu Kezhen led a group of scientists conducting investigations on the Hainan Island and the Peninsula of Leizhou. The findings of this group were summarized in a report by Dr. Zhu in the same year. His observations may be briefly stated as follows.1. The development of tropical land will inevitably lead to conversion of the natural ecosystems (biogeozenes) to more productive systems to better serve the society.2. Much attention was paid to the plantation of tropical economic crops. With respect to rubber, the selection of suitable land, shelter belt, vegetal cover, soil conservation and high yielding cultivars adapted to the environment of Hainan were strongly recommended. About the same applied to other tropical crops as well, but, in addition, research on plants naturally growing in the region was stressed.3. Self-sufficiency in staple food production should be the minimum goal, while the extension of sugarcane and pineapple cultivation to meet the need of other regions of China was advocated. Distribution of crops in conformation with the physical environment was advised,and along with this, diversification was suggested. Efforts were called to establish sustained production systems. Measures to increase food production as stipulated included better land management, higher yield and increased multiple cropping. Development of irrigation and expansion of fertilzer supply were mentioned as the key to higher yield of food crops.Livestock production was viewed as a means both to provide meat and other animal products and to supply manures for crops. Green manures and local resource of liming materials were also regarded as important to raising crop productivity.4. Deforestation and other vegetation destruction was seriously worried about for its inducement to soil erosion and its harmful effect on water resour-es. Importance was tacitly accorded to forestation, as witnessed by much discussion in the report on tree species adaptable to various types of terrain. In connection with forestation, firewood production end again shelter belt establishment were reted as useful and indispensable. Nature reserve was also tacitly highly valued, since it was strongly recommended in his other reports.Since 1957, significant progress has been made in scientific research on tropical environment of the world. Simultaneously, considerable changes have taken place in Hainan. A no small fraction of rubber plantation has gone around to attain fairly high productivities mainly consequent upon the adoption of measures stated in 1. There has been a growth in agricultural production, but still part behind self sufficiency in staple food. Remarkable achievements have appeared in scene in planting quick growing trees in some coastal tracts. Irrigation has developed on a moderate scale, although leaving much to be desired.Changes may be noted in all other aspects, but not impressive.A tragedy is that annual forest depletion surpasses annual forest growth. The need to reverse the tendency is becoming more and more urgent. In view of the recent advances in scientific knowledge of the tropics and developments in the situation of Hainan, the majorty of Dr. Zhu's observations in 1957 still hold good today.Recently numerous investigations have been undertaken on the problems of the development of Hainan. In the Symposium on Hainan in Guangzhou in 1983, organized by the China Association for Science and Technology, a number of proposals were presented. I agree with most of them. But their implementation would require many years and heavy overhead expenditures. In my opinion, Leucaena leucocephala may serve as cheap alternatives for the solution of many problems.It will supply fuelwood, timber,wood pulp, fertilizers and animal feed, control soil erosion, slow down deforestation, improve soil properties, and help to make reforestation less difficult.Its potentialities are not fully understood.