All-optical wavelength conversion based on transient cross phase modulation of semiconductor optical amplifier (SOA) is a promising approach to achieve high-speed all-optical signal processing. We experimentally demonstrate inverted and non-inverted wavelength conversion (WC) based on single SOA and an optical bandpass filter with 0.4 nm bandwidth. When the central wavelength of the following filter is blue shifted by 0.25 nm or red shifted by 0.05 nm with respect to the wavelength of probe signal, the WC is inverted. When the filter detuning is blue shifted 0.29 nm or red shifted 0.25 nm, the WC is non-inverted. The polarity evolution from inverted WC to non-inverted WC is also presented with numerical simulation. The obtained results are in good agreement with the experiment.