High temperature in summer often leads plants to lose water and even to die, which is a serious problem in application of solid soilless substrate in vertical greening. In order to solve this, the water retention of the traditional substrate, the imported solid soilless substrate ‘Pafcal’, and the domestic solid soilless substrate ‘Tan Mian’ were compared, and a comprehensive evaluation on the drought adaptability of 7 landscape plants, including Hedera nepalensis, Trachelospermum asiaticum‘Ougonnishiki’, Ligustrum quihoui Carr., Ligustrum japonicum ‘Howardii’, Serissa japonica ‘Variegata’, Gardenia jasminoides cv. prostrata and Ligustrum japonicum ‘Jack Frost’, were carried out by factor analysis, using drought stress response time, recovery after rewater, endogenous substances content and protective enzyme activity as indexes. The results showed that: (1) the traditional substrate had the strongest water retention, and ‘Tan Mian’ had stronger, while ‘Pafcal’ had the worst; (2) all of the plants in the traditional substrate had the longest drought stress response time, and which in ‘Tan Mian’ had longer, while which in ‘Pafcal’ had the shortest; (3) after rewatering, most plants in traditional substrate recovered much better than that in solid soilless substrates, but H. nepalensis and G. jasminoides cv. prostrata recovered well in solid soilless substrates; (4) MDA content and POD activity of most pants in all substrates increased firstly and then decreased; SOD activity of H. nepalensis and L. japonicum ‘Jack Frost’ in ‘Tan Mian’ at 20 d increased markedly, yet which of the other plants showed no significant changes in all substrates; soluble protein content showed the same variation trend in all substrates, which was that H. nepalensis and S. japonica ‘Variegata’ continuously decreased, while the others increased firstly and then decreased; (5) H. nepalensis, L. japonicum ‘Jack Frost’ and Serissa japonica ‘Variegata’ had extremely strong drought adaptability in the traditional substrate, yet H. nepalensis, S. japonica ‘Variegata’ and L. japonicum ‘Howardii’ had strong drought adaptability in both two solid soilless substrates.