Abstract: The paper deals with the niche measurement of the dominant population of scrub in Huairou mountainous region of Beijing area. The niche breadth of 20 dominant species is calculated by using the Shannon-Wiener index and the niche overlap between those species is measured by applying the coefficient of similarity along the community and altitude gradient. It is shown that the method of measuring the niche breadth and the niche overlap is highly effective for the scrub research.