The emissivity uniformity of a blackbody cavity can be determined by emissivity at different locations and areas. We used the Monte Carlo method to calculate the local normal effective emissivity and average normal effective emissivity of isothermal concave cone, cylinder cone, cylinder, and cylinder-inner cone cavities with an identical length-radius ratio of six. The cylinder cavity has the highest uniformity, followed by the cylinder cone, cylinder-inner cone, and concave cone cavities. A cavity with both high uniformity as the cylinder cavity and insensitivity to specular reflection as the cylinder cone cavity has been demonstrated.