Fe-rich regions of the Ce-Fe-{Ni, Si, Al}-B quaternary systems were studied and screened for magnetic phase identification. The main magnetic phase found in these systems is the 
Ce2(Fe14-xTx)B solid solutions, where T denotes Ni, Si or Al. No new Fe-rich magnetic phase was discovered. Fe-rich regions of the Ce-Fe-{Ni, Si, Al}-B quaternary systems were experimentally studied using diffusion couples and selected key alloys annealed at 900OC. Homogeneity ranges of Ce2(Fe14-xNix)B, Ce2(Fe14-xSix)B and Ce2(Fe14-xAlx)B solid solutions were measured to be (0 ≤ xNi ≤ 1.5), (0 ≤ xSi ≤ 2.33) and (0 ≤ xAl ≤ 2.5), respectively. 
Magnetic force microscope analysis was used to screen out non-magnetic phases. Among the phases observed in the Fe-rich regions of the Ce-Fe-{Ni, Si, Al}-B quaternary systems, only the quaternary extensions of Ce2Fe14B show visible magnetic domains. Using thermogravimetric analysis and physical property measurement system, further tests were performed to quantify the intrinsic magnetic properties of the Ce2Fe14B quaternary extended solid solutions. This is to reveal the effect of modifying Ce2Fe14B ternary compound by Ni, Si and Al additives on its intrinsic magnetic properties. Modifying Ce2Fe14B ternary compound with these additives showed decrease in the saturation magnetization and anisotropy field. But in the case of Curie temperature, Ni and Si additives increase the Curie temperature of Ce2Fe14B ternary compound while Al additive reduces its Curie temperature.