A clock buffer circuit is provided. The clock buffer circuit receives an input clock signal and generates a delay clock signal. The clock buffer circuit includes an input circuit, an output circuit, a first delay path, and a second delay path. The input circuit receives the input clock signal and generates an output clock signal according to the input clock signal. The output circuit generates the delay clock signal. The first delay path is coupled between the input circuit and the output circuit. The second delay path is coupled between the input circuit and the output circuit. The input circuit selectively provides the output clock signal to a first specific delay path among the first and second delay paths according to a control signal. The output circuit receives the output clock signal which passes through the first specific delay path and outputs the delay clock signal.
