To screen tree species with strong water holding capacity, the indoor extraction method was adopted to analyze the leaf characteristics such as leaf length, leaf water holding rate, water absorption rate, water loss rate and water loss rate of 8 garden tree species including Cercis chinensis. The water retention rate and immersion time of the leaves, the water loss rate and water loss time, the water absorption rate and immersion time of the leaves, and the water loss rate and water loss time were functively fitted to analyze the correlation between the leaf characteristics and the water retention performance. The results showed that, (1) the maxium leaf water holding rates of the 8 garden tree species, from high to low, were as follows: Diospyros lotus (346.27%)>Fraxinus chinensis (345.23%)>Rosa chinensis (314.87%)>Cercis chinensis (282.13%)>Chaenomeles speciosa (229.47%)>Photinia serratifolia (198.60%)>Buxus sinica var. parvifolia (179.20%)>Buxus megistophylla (150.27%); the maxium water loss rates of leaves, from high to low, are as follows: Diospyros lotus (56.49%)>Photinia serratifolia (55.86%)>Chaenomeles speciosa (52.77%)>Rosa chinensis (52.56%)>Cercis chinensis (49.76%)>Buxus sinica var. parvifolia (49.34%)>Fraxinus chinensis (45.60%)>Buxus megistophylla (41.73%). (2) With the increase of soaking time, the water holding rate and water loss rate of the leaves of the 8 garden tree species showed a logarithmic function relationship, while the water absorption rate and water loss rate showed a power function relationship. (3) The maximum water holding capacity of leaves was closely related to the specific leaf area. In conclusion, the water holding capacity of Diospyros lotus, Fraxinus chinensis and Rosa chinensis was relatively good, and they had a strong ability to conserve water sources. The research results provide a reference for the selection of tree species to optimize the water conservation function of urban green spaces.