– We demonstrate predictable resonance wavelength shifts in silicon micro-resonators by varying their perimeters using high-resolution lithography. The linear coefficient between the resonance wavelength shifts and the perimeter changes is determined with detailed experiments, and found to be nearly constant across the C and L bands in telecommunications. This empirical coefficient is also compared to that obtained from simulations on straight waveguides. Based on the linear model, without post-fabrication trimming or tuning, an eight-channel wavelength de-multiplexer with reasonably predicted average channel spacing ~ 1.8±0.1 nm (3dB bandwidth ~ 0.7±0.1 nm) is demonstrated at telecommunication bands in a silicon chip for the first time. This filter has out-of-band rejection ratio ~ 40 dB, low channel crosstalk ≤ 30 dB and low channel dropping loss ≤ 4±1 dB except for degraded performance in one channel due to fabrication imperfections.