It is pointed out that the total milk yield is equal to the physiological milk yield plus nutrition milk yield and climate milk yield,that is,Y_total=Y₁+Y₂+Y₃.It is focused on the climate milk yield and nutrition milk yield. The result shows that the four factors,ie,monthly average vapour pressure,monthly average air temperature,monthly average lowest temperature and monthly average evaporation,have great effect on the climate milk yield.Meanwhile,the best conditions in the monthly average vapour pressure (1988),monthly average air temperature (1993),monthly average lowest temperature (1989) and monthly average evaporation (1988) are the most favourite for the climate milk yield .The cause of the low milk yield was given,that is,the milk production peak is postponed for 30 days.What’s more,if the seed amaranth can be planted to make up for the cow food shortage during July and August,there is a potential milk production increasement of 1 million kilograms.