A three-dimensional tubular quantum well infrared photodetector (QWIP) was demonstrated via rolled-up technology, which is on the basis of conventional lithography and wet chemical etching. When the tubular QWIPs and the corresponding planar devices were illuminated by the vertically-incident light, their dark current, blackbody response, and photocurrent responsivity spectra were characterized. Under the operating temperature of 60 K and the bias of 0.45 V, a peak responsivity of 20.6 mA/W and a peak quantum efficiency of 2.3% at the peak response wavelength of 3.62 μm were obtained in the tubular devices. By clarifying the principle of optical absorption, the tubular QWIP presents a novel optical coupling manner. The photocurrent responsivity spectra of the device for the external light were further studied at different incident angles. It is shown that with the approximately circular symmetry of the microtubes, the tubular devices have a wide perspective, which is advantageous to the design of infrared detection system.