All-optical wavelength converter (AOWC) is one of the key components in all-optical communication network.It′s an essential device for optical wavelength routing. A wavelength conversion scheme by cross-phase modulation (XPM) in chalcogenide fiber is proposed in this paper .A modulated signal and a reference signal are led into a common chalcogenide fiber for XPM,and followed b y an optical band-pass filter (BPF).Either side-band of the BPF′s output can be used to recover the origin al digital signal by phase-intensity conversion.Theoretical analysis and simulation for this proposed scheme are pro vided.Due to the large nonlinearity coefficient of the 1-m-long chalcogenide fiber,the peak power of the modulated signal required for XPM is really low,thus the ultra-short pulse laser is no longer needed.As a case,the modulated signal is obtained by a 40Gbit/s return-to-zero digital signal driving Mach-Zehnder mo dulator (MZM).The eye diagrams of the converted light signal at 1550nm wavelength show good performance.Compared with the or iginal signal,there is only 1dB power penalty.Since there is no more special treatment needed for the chalcogenide fiber to reduce i ts chromatic dispersion,the proposed scheme is easy to realize,and it has a great prospect of applicati on in high-speed all-optical transmission systems.