The study of the F₂-layer properties and the critical frequency(foF₂) is necessary to understand the dynamic features and thus more accurately predict the behavior of the F layer, and this research aims to find the relationship (correlation) and interdependence between the critical frequency (f_oF₂) of Ionospheric layer F₂ and Sunspot number. In this study the characteristics and behavior of F₂ layer during Solar cycle 24 were studied, the effect of Sunspots number (Ri) on the critical frequency (f_oF₂), were investigated for the years (2012, 2013, 2014) which represents the ascending phase and 2014 represent the peak phase of the solar cycle 24 over Kirkuk city (35° N, 44° E) by finding the critical frequency (f_oF₂) values, the layer’ s impression times are determined for the days of solstice as well as equinox, where the solar activity was examined for the days of the winter and summer solstice and the days of the spring and autumn equinoxes for a period of 24 hours by applied the International Reference Ionosphere model IRI (2016). The output data for f_oF₂ were verified by using the IRI-Ne- Quick option by specifying the time, date and Sunspot number parameters. Statistical analysis was caried out through the application of the Minitab (version 2018) in order to find the correlation between the critical frequency (f_oF₂) of Ionospheric layer F₂ and Sunspot number. It was concluded that the correlation is strong and positive, this indicate that critical frequency (f_oF₂) increase with increasing Sunspots number (Ri) for solar cycle 24.