The method including the treatment of lysozyme was investigated for the preparation of DNA from amylase-producing bacteria, Bac. subtilis var. amyloliquefaciens Fukumoto. By discussing the procedure tested, it was demonstrated that the method outlined as follows was most suitable for this strain of bacteria. Acetone-dried cells of bacteria were lysed by the action of egg-white lysozyme, either fresh crystals or freeze-dried powder in vacuo, at 37゜ overnight in the presence of some DNase inhibitor such as Na-citrate or PCMB. Lysate was poured into 2 volumes of ethanol and the precipitate produced was collected. The precipitate was dissolved in 2 M NaCl, treated with chloroform according to Sevag and DNA fraction was again precipitated with alcohol from deproteinized clear solution. The precipitate was then dissolved in l0 % CaCl_2 solution. The fibrous precipitate was produced by adding 0.3 volumes of ethanol into CaCl_2 solution and dissolved in 2 M NaCl. Since protein which could not be removed by first procedure of deproteinization became to be dissociated, it was treated repeatedly with chloroform. Finally, DNA fiber and powder were deposited with alcohol and dried in vacuo after stepwise washing them with alcohol of increasing concentration and finally several times with ether. Alternatively, protoplast of amylase-producing bacteria was made from dried-cell by the action of lysozyme at 37℃ for 30 min. and extracted with 2 M NaCl. White fiber or powder of DNA could be prepared by the same procedure. Similar properties of nucleoprotein and nucleic acids of the bacteria, reported in the foregoing paper, were observed and turned to account in this case too.