Fertility levels are being measured. by several indicators. Some of these indicators are: Total fertility rate (TFR) , General fertility rate (GFR), Crude birth rate (CBR), Age at first marriage, Age at first birth, Age at last birth, Birth intervals, Number of children ever born, Number of living children, Parity. progression ratios, and Net reproduction rate. Some of these indicators are discrete variables such as Number of children ever born and Number of living children. Others are theoretically continuous such as the rates and those indicators related to age (age at first marriage,  ..)- Of course, these indicators can be partitioned to create ordinal variables. Fertility levels are being measured by several indicators. This paper introduced brief definitions to some of these indicators and its estimation analysis methodologies