Abstract: Urban park green space, the main body of the urban landscape system, is a place epitomizing plant diversity in a city. The study of the plant diversity can provide the basis for the protection of urban biodiversity. This paper takes 17 multi-functional parks in Taiyuan City, Shanxi Province, as the research objects to analyze plant diversity in the perspectives of plant application values, Margalef richness, Shannon-Wiener diversity and Pielou uniformity, providing references for the protection of plant diversity and green space construction in the parks of Taiyuan. The results show that there are 285 species of plants that belong to 164 genuses of 78 families in Taiyuan multi-functional parks. The top five species in terms of plant application importance values are Buxus megistophylla> Berberis thunbergii var. atropurpurea> Sabina chinensis> Sophora japonica> Ligustrum vicaryi. The plant richness index is 26.42, with tree layer> grass layer>shrub layer. The diversity index is 3.13, with tree layer>shrub layer. The evenness index is 0.60, with tree layer>shrub layer. The parks with high overall evaluation of woody plant diversity are Fenhe Park, Yumenhe Park and Jinci Park. Those with low evaluation are Yingshanhu Park, Changfeng Business District platform landscape greening, and Nanhaizi Park.