The proteinpolysaccharides (PPS) from Polyporus umbellatus (P. umbellatus) screlotium is composed by 78.2% of saccharide, 16.8% of protein, and 4.0% of ash. PPS from P. umbellatus showed antitumor activities against 180 solid tumor in ICR mice at the concentration of 20~160 mg/kg/day. PPS from P. umbellatus inhibited cell viability to 47.4% and 45.0% in leukemia cell lines, L-1210 and K-562 cells at 50~400 ㎍/mL concentration, respectively. But the hall mark of cell apoptosis, DNA fragmentation was not observed at those concentration. 2.5~10.0% of PPS from P. umbellatus inhibited mutagenecity evoked by 2-nitrofluorene and sodium azide in Salmonella typhimurium TA 98 and TA 100.