The effect of period, season and parity of calving was studied on 936 lactations of 311 Murrah buffaloes spread over a period of 31 years from 1970–2000. Period of calving had significant (P 0.01) influence on peak yield (PY), days to attain peak yield (DAPY), total yield up to peak (TYP), average dally milk yield up to peak (DMYP) but rate of increase up to peak yield (RINCPY) dd not influence significantly by period of calving. Season of calving and parity showed non-significant effect on all the above traits except effect of parity (P < 0.01) on peak yield. The least-squares means for PV, DAPY, TYP, DMYP and RINCPY were 7.90±0.08 kg, 45.47±1.32 days, 239.75±7.80 kg, 5.22±0.07 kg and 0.153±0.006 kg/day, respectively. The h2 values were 0.67±0.17, 0.68±0.17 and 0.73±0.17 for DAPY, DMYP and RINCPY, respectively.