1. The multiple forms of acid phosphohydrolases in liver lysosomes of Sus scrofa domesticus and Gallus gallus domesticus were studied by use of isoelectric focusing. 2. Acid phosphatase was resolved into two forms in G. gallus domesticus and three forms in S. scrofa domesticus. Especially, two forms of G. gallus domesticus were different from each other in their enzymatic properties. 3. The pI values of acid ATPase agreed with those of acid phosphodiesterase in G. gallus domesticus. According to the data on activity ratios, however, these enzymes seemed not to be identical. 4. Except acid deoxyribonuclease, extraction by Triton X-100 of lysosomes increased the proportions of acidic forms of these enzymes. In particular, a new form of acid ribonuclease with pI 4.5 or 4.9 appeared in both cases of G. gallus domesticus and S. scrofa domesticus.