A total of 1561, 575 and 2337 normal lactation records of Baladi, Friesian and their crosses cows respectively were used in the present study. The three genetic groups belonged toELGemeza farme Animal Production Research, institute, Ministry of Agriculture, during the period from 1975 to 2011. Trait studied are 305 day milk yield (305 d MY) and lactation period (LP).  Data were analyzed by using Multi Trait Animal model (MTAM). The model includes the fixed effects of month and year of calving and parity and the random effects of animal, permanent environmental and errors. Average 305 d MY was 1160, 2098 and 1695 kg, for Baladi, Friesian and crossing, respectively. Mean of LP was 210, 272 and 248 d, for the three groups, respectively.  Month and year of calving and parity had highly significant effect on 305 d MY and LP. Heritability estimates for 305 d MY ranged from 0.06 to 0.39 for the three groups and LP ranged from 0.05 to 0.28.  Genetic correlation among two traits ranged from 0.40 to 0.96, while phenotypic correlation  ranged from 0.50 to 0.70.