Keywords: 
• Landscape architecture /
• sunshine analysis /
• street trees /
• Haikou

Abstract: In order to study the layout of street trees in tropical cities, the height and crown width of street trees as well as road width and the building height on both sides of the roads were measured in Haikou city with Haikou city as an example. The data collected was used to analyze the sun exposure to the street trees by using the SketchUp software. The results showed that there was no difference in daylight exposure duration of the street trees between the east and west sides of the north-south roads. The height of buildings and the height of street trees had a great influence on the sunshine duration of the street trees, while the width of roads generally had no effect on the sunshine duration of the street trees. The street trees along the east-west roads had longer sunlight exposure duration in the north than in the south. The height of building, the height of the street trees and the width of the roads had obvious influence on the sunshine duration of the street trees. In this context a strategy for layout of street trees was put forward. Under the same circumstances in the north-south roads where buildings are not high on both sides of the roads big shade trees, such as Ficus benjamina, Ficus altissima, Bischofia javanica, etc, are recommended for planting along both sides of the roads, or on the contrary if the buildings are high small trees such as Bauhinia purpurea, Sterculia lanceolate, etc are selected. If the road runs from east to west, big shade trees, such as Ficus altissima, Ficus benjamina, etc, are selected for planting on the north side, and small trees, such as Sterculia lanceolate, Bauhinia purpurea, etc, are planted on the south side of the road. In the narrow roads where buildings are high on both sides it is better to plant street trees in one side or plant shade shrubs, such as Bougainvillea glabra, Carmona microphylla, Fagraea ceilanica, etc.