In preliminary screening for actinomycetes, thirty soil samples collected from six caves in Changwat Kanchanaburi, Ratchaburi and Saraburi were used. The percentage of actinomycetes isolated from caves namely: Mungkorn-tong, Kao-lam, Sarika, Jom-pon, Kao-bin and Pothisat were 2.23, 3.92, 7.23, 0.16, 1.16 and 0.84 respectively. The net per cent of isolated actinomycetes was 3.81.
