A phase interpolation device and a multi-phase clock generation device are provided. The phase interpolation device includes a digital controller circuit and a phase interpolator that includes a capacitor and circuit branches, which are controlled by the digital controller circuit to generate an n-th phase clock of N phase clocks between first and second input clocks. When the n-th phase clock is generated, the digital controller circuit controls, in response to appearances of rising edges of the first input clock, the circuit branches to charge the capacitor using (N−n+1)×M ones of the first current source, and controls, in response to appearances of rising edges of the second input clock, the circuit branches to use N×M ones of the first current source to charge the capacitor. N, M, n are integers.