A wavelength tunable resonant cavity enhanced photo-detector grown on GaAs is fabricated. The quantum wells of In0.25Ga0.75As/GaAs in the active region are grown by molecular beam epitaxy. The peak of the response spectrum at 0 work bias is located at 1071 nm. When the tuning voltage rises from 0 V to 21 V, the peak shows a blue shift of 23 nm, reaching 1048 nm. Statistical results show that there is a stable accurate corresponding relation between the tuning voltage and the response peak. The relation is approximately linear when the tuning voltage is greater than 5 V. Some theoretical analysis is performed on the test results.