Rubber plantations in Southeast Asia have expanded greatly in recent decades, thereby increasing the amount of edges bounding natural forests. In this study, we focused on the effects of rubber plantation-forest edges on species diversity and abundance of web-building spiders. We also aimed to reveal environmental determinants that influence such patterns. We visually searched and collected spiders within 85 quadrats from October to January (heavy rain period), and 160 quadrats from May to September (light rain period). The quadrats were placed in five sites representing rubber plantations, rubber plantation-forest edge, and forest interior up to 150 m from the edge. We examined understory characteristics, microclimate, and potential prey within each quadrat. Certain species were abundant in rubber plantations, others were abundant at the edge or within the forest, and others showed no pattern. Species richness was not related to the edge whereas species diversity and total abundance of the spiders was higher in the rubber plantation and decreased at the rubber plantation-forest edge and into the forest interior. Temperature range and average temperature appear to drive the distribution patterns of species diversity and total abundance. Characteristics of understory, namely dry twigs and seedlings also tended to affect such patterns. Temperature probably affected the spiders' ability to maintain favorable body temperatures whereas dry twigs and seedlings probably provide reliable web support and suitable refuges.