Ionized gas is one of the primary components of the interstellar medium (ISM) and plays a crucial role in star formation and galaxy evolution. Radio recombination lines (RRLs) can directly trace ionized gas in HII regions and warm ionized medium (WIM) without being affected by interstellar extinction. Single-dish telescopes like Arecibo Observatory are sensitive to low surface brightness emission, and are therefore powerful tools for the study of HII regions and the WIM. We report here on a large surveys of RRL emission: The Survey of Ionized Gas in the Galaxy, Made with the Arecibo telescope (SIGGMA). It is the first large-scale fully-sampled RRL survey, and covers the whole observable inner Galactic plane by the Arecibo telescope (l = 32 - 70 deg). It is performed with the Arecibo L-band Feed Array (ALFA) receiver, whose bandpass covers twelve hydrogen alpha lines from H163α to H174α. By stacking the α-lines and smoothing to 5 km/s velocity resolution, the final SIGGMA spectra have a mean rms level of ~0.65 mJy per beam. Here, we report on early analysis of the SIGGMA data and present first scientific results.