The influence of freezing-thawing on the activity of recombinant L-phenylalanine-ammonia-lyase has been investigated. Conditions of liophilization of recombinant L-phenylalanine-ammonia-lyase at which enzyme loses about 10% of activity in a single freeze-thaw cycle are chosen. Dependence of cryoscopic temperature of enzyme from concentration of protein in a preparation is studied. The optimum temperature of freezing of enzymatic preparation L-phenylalanine-ammonia-lyase for sublimatic drying is chosen.