This study was conducted to provide basic data for the development of natural seasoning. The quality chatacteristics of water exacts from Pleurotus ostreatus and Lentinus edodes were determind. Also, savory taste, fragrance, color and overall preference was evaluated. The preference test on the seasonings prepared from Pleurotus ostreatus and Lentinus edodes with the addition of sea tangle was also performed. The crude protein content of dried, Lentinus edodes and Pleurotur ostreatus was 20.4% and 30.4% respectively. The total organic acid contents were higher in Plourotus ostreatus than in Lentinus edodes extracts. The total free amino acid adn total nucleotide contents were higher in Pleurotus ostreatus than in Lentinus edodes extracts. Three nucleotide, adenosine monophosphate(AMP) , guanosine monophosphate(GMP), xanthine monophosphate(XMP) were found in mushroom seasonings while inosine monophosphate(IMP) was not detected. Pleurotus ostreatus extract showed higher score in savory taste and overall acceptability than Lentinus edodes extract, Pleurotur ostreatus seasoning added with 1% sea tangle and Lentinus edodes seasoning added with 1.5% sea tangle were rated as high in overall quality In a sensory test of foods cooked with mushroom seasoning. It was shown that panels in their twenties well used to the taste of monosodium glutamate while the people in their thirties preferred the specific flavor of the mushroom seasoning.