The 16 low resolution spectrographs (LRS) have been successfully commissioned for the LAMOST. The LRS design employs a dual-beamed and bench-mounted, with large-beamed, fast Schmidt cameras and Volume Phase Holographic (VPH) transmission gratings. The design wavelength range is 370-900nm, at resolutions of R=1000and R=10000. Each spectrograph is fed by 250 fibers with 320 micron in diameter (corresponding 3.3 arcsec), composed of one F/4 Schmidt collimator, a dichroic beam-splitter, four VPH gratings, articulating Schmidt cameras that are optimized at blue band

(370-590 nm) and red band (570-900 nm), and field lens near the focal plane service as the vacuum window of CCD detector cryogenic head. In this paper, we present the testing result of the LRS on the image quality, spectra resolution, efficiency and observing spectra.