The protoplasts of Candida utilis 295 t were produced with the aid of the lytic enzyme from Helix pomatia. If the cell wall of C. utilis 295 t is not treated with SH-compounds (the best effect was found with L-cysteine), it is resistant to the action of the enzyme. The yield of the protoplasts was 100 per cent after 15 minutes of the incubation with the lytic enzyme if the cells were preliminarily treated with L-cysteine. Optimal conditions for the production of the protoplasts are described.