Distinctions between shallow and deep tunnels are conducive to pursuing suitable strategies for tunneling. This paper first examines the current practices on the rules for distinctions between shallow and deep tunnels and then conducts both theoretical and numerical analyses of these rules for tunneling in homogeneous ground, to shed some observations on the relevant issues: (1) The distinction depth increases when the prescribed ground pressure ratio decreases and vice versa. (2) For a specific ground pressure ratio value, the worse the rock stability, the larger the distinction depth. (3) The distinction depths calculated by using the Terzaghi formula are more conservative than the China design code. (4) The distinction depths by using the Protodyakonov formula are even more conservative. (5) The distinction depths by using the Terzaghi formula can be verified by finite element simulations of tunnel excavations.