We fabricated 1$ imes$8 array of GaAs/AlGaAs quantum well infrared photodetectors for the long wavelength infrared detection which is based on the bound-continuum intersubband transition, and characterized its electrical and optical properties. The device was grown on SI-GaAs(100) by the molecular beam epitaxy and consisted of 25 period of 40 ${AA} $ GaAs well and 500 ${AA} $ $Al_{0.28} Ga_{0.72}$ As barrier. To reduce the possibility of interface states only the center 20 ${AA} $ of the well was doped with Si ($N_D=2{ imes}10^{18} cm^{-3}$). We etched the sample to make square mesas of 200$ imes$200 $mu extrm{m}^2$ and made an ohmic contact on each pixel with Au/Ge. Current-voltage characteristics and photoresponse spectrum of each detector reveal that the array was highly uniform and stable. The spectral responsivity and the detectivity $D^＊$ were measured to be 180,260 V/W and $4.9{ imes}10^9cmsqrt{Hz}/W$ respectively at the peak wavelength of $lambda$ =7.8 $mu extrm{m}$ and at T=10 K.