The aim of this research was to evaluate weathered spent mushroom substrate (SMS),made from spent Flammulina velutipes mushroom substrate,as a growing medium for nursery seedlings.Two vegetable species,cucumber (Cucumis sativus L.cv.Jinchun No.2) and tomato (Solanum lycopersicum L.cv.Mandy),were grown in 8 media of SMS in various ratios with perlite or vermiculite.A mixed substrate of peat with perlite (1:1;v:v) was used as the control (CK).The experiment was arranged in a completely randomized design under greenhouse conditions.Prior to sowing,some physical and chemical properties of the growing media were determined.Results showed that all the mixtures had desirable physical and chemical properties for their use in nursery tomato and cucumber seedlings except for the T4 (SMS:vermiculite=1:1;v:v) and the T8 (SMS:perlite=2:1;v:v) mixtures.Compared with the CK,increased plant height,leaf area,fresh weight,dry weight and index of seedling quality were found in the T3 (SMS:vermiculite=2:1;v:v) and T6 (SMS:perlite=4:1;v:v) growing media.SMS should be considered as an alternative for the widely used but expensive and resource-limited peat in greenhouse cultivation. The aim of this research was to evaluate weathered spent mushroom substrate (SMS), made from spent Flammulina velutipes mushroom substrate, as an growing medium for nursery seedlings.Two vegetable species, cucumber (Cucumis sativus L. cv. Jinchun No. 2) and tomato (Solanum lycopersicum L.cv.Mandy), were grown in 8 media of SMS in various ratios with perlite or vermiculite. A mixed substrate of peat with perlite (1: 1; v: v) was used as the control (CK) Prior to sowing, some physical and chemical properties of the growing media were determined. Results showed that all the mixtures had desirable physical and chemical properties for their use in nursery tomato and cucumber. The seedlings except for the T4 (SMS: vermiculite = 1: 1; v: v) and the T8 (SMS: perlite = 2: 1; v: v) mixtures. Compared with the CK, increased plant height, , dry weight and index of seedling quality were found in the T3 (SMS: vermiculite = 2: 1 ; v: v) and T6 (SMS: perlite = 4: 1; v: v) growing media. SMS should be considered as an alternative for the widely used but expensive and resource-limited peat in greenhouse cultivation.