Clinically healthy 66 female Maniker breed chicken(22 of 2-week-old : group A, 23 of 8-week-old： group B and 21 of 27-week-old： group C) and 66 female Manina breed chicken (21 of 2-week-old : group D, 22 of 8-week-old : group E and 23 of 27-week-old : group F) were examined to establish physiological basic data on serum total Creatine phosphokinase (CPK) activities and CPK isoenzymes fractions. The results obtained were summarized as follows； 1. Serum total CPK activities were $1,088{pm}254.0;IU;/{ell},$ $1,454{pm}337.2;IU;/{ell}$ and $1,440{pm}526.3;IU;/{ell}$ in gorup A, group B and group C of Maniker breed, respectively. Group B and group C showed higher values than that of group A (P<0.01) meaning high values nth aging. 2. Serum total CPK activities were $1,676{pm}420.5;IU;/ {ell},$ $1,007{pm}283.1;IU;/{ell}$ and $862{pm}294.5;IU/{ell}$ in group D, group E and group F of Manina breed, respectively. Group D showed the highest value among groups (P<0.01) and Manina breed showed the low values of serum total CPK activities with aging. 3. Manina breed at 2-week-old and Maniker breed at 8-week-old and 27-week-old showed significant high values of total serum CPK activities in breed differance (P<0.01) 4. In the pattern of serum CPK isoenzyme fractions, group A and group B were high with decreasing order of $CK_3>CK_2>CK_1$ and group C was high with decreasing order of $CK_2> CK_3>CK_1$ Groihp D, E and F showed the same pattern with decreasing order of $CK_2>CK_3> CK_1.$ 5. Significance of CPK isoenzymes fractions in breed differance was only found at 8-week-old. $CK_1;and ;CK_3$ in Maniker breed (P<0.05), and $CK_2$ in Manina breed were higher than that of the other breed (P < 0.01).