Since laser-ablation plasmas have significant spatial distributions with transient properties, the diagnostic techniques should have temporal and spatial resolutions. Laser-induced fluorescence (LIF) imaging spectroscopy, which can visualize the distributions of particle densities in plasmas, is a suitable method for the diagnostics of laser ablation plasmas. This report describes our system of LIF imaging spectroscopy. Although LIF imaging spectroscopy is an excellent diagnostic technique, in this report, we dare to discuss some problems of LIF imaging spectroscopy to clarify the limitations in the application to laser-ablation plasmas.