Cultured on selective medium based on feldspar as its sole potassium source, 17 strains of silicate-dissolving bacteria were screened out of soils sampled from several provinces in China. Their physiological and biochemical characters, salt tolerance, antibiotic resistance, temperature sensitivity and K releasing capability were determined. The results show that all strains appear as rods and yield ellipsoidal spores, but Strains SB6 and SB13 are shorter. The Gram reaction of Strains SB4, SB6, SB10 and SB15 were positive and the others negative. The isolates grew well with NH₄⁺ and NO₃^-as nitrogen source and survived without. The strains were compared in capability of releasing potassium and it was found that Strain SB13 and NBT were more capable of releasing potassium. The content of soluble potassium was increased by 49.1% and 45.3%, respectively. Strains SB2, SB4, SB5 and SB6 survived in the medium with 20.0 g/L NaCl and were growing well under the temperature ranging from 10℃~40℃.