The ash and silica content of 21 species of commercial woods of Surinam have been quantitatively determined.The results show that the silica contents of Manilkara sp.,Dicorynia sp.,Qualea sp.and D.guianensis are comparatively high,which are 0.934%,0.759%,0.740%,0.698% respectively;the silica contents of Hymenaea sp.,Ocotea caudata and O.rubra are comparatively low,which are 0.026%,0.035%,0.040% respectively;the silica contents of Tabebuia sp.and Martiodendron parvilorum are the lowest,which are 0.006%,0.007% respectively.