Abstract: To study the feasibility of using used mushroom cultivation medium as substrate in producing seedling pots of non-woven fabric with seedling pot shaping machine（SPSM）,physico-chemical properties and salinity leaching characteristics of the substrates of used medium and peat for production of seedling pots were determined and their effects on germination and growth of seedlings of Rhus typhina and Platycladus orientalis were discussed.Results show that the pot of used medium does not differ much from that of peat in bulk density and aeration.Relative to the latter,it is obviously higher in pH than the latter,but still in a suitable range for growth of most plants,lower in water and nutrient holding capacity,in suitable water range（36.1% ～143.5% versus 41.9% ～193.8%）,and in absolute content of available water as well.Its electric conductivity is 3.71 mS·cm-1,higher than the threshold value,≤2.6 mS·cm-1,for seedling nursing,but it could be lowered down below the safety value after frequent watering.Beside,it is much higher than the pot of peat in content of total nitrogen,total phosphorus and total potassium.Under the condition of adequate water and nutrients,the two pots are more or less the same in effect on germination and survival rate of the seeds of Rhus typhina and Platycladus orientalis.And the pot of used medium is much better than the pot of peat in effect on growth of the seedlings of Rhus typhina.So it is obvious that as long as the water supply is adequate in culturing Rhus typhina and Platycladus orientalis seedlings,used mushroom cultivation medium is good enough to replace peat in producing seedling cultivation pots of non-woven fabric.