Using the polycrystalline material synthesized via solid-state reaction, Li2MoO4 single crystals were grown by vertical Bridgman method. The crystal defects, deliquescence properties and IR spectra were investigated in detail. The crystal defects can be attributed to the fast cooling rate, the high rate of crystal growth and the large size of crystal. Crystal deliquescence was verified to be only a physical change by identifying the phase components. The Silk-like inclusions embedded inside the crystal medium have great effects on the optical transmittance of crystal material. The polished crystal without silk-like inclusions exhibits an optical transmittance as high as 82-85% in 400-800 nm, while the crystal wafer containing silk-like inclusions shows an optical transmittance decline in 400-800 nm. In addition, the silk-like inclusions inside the crystal medium were verified to contain the molybdenum-enriched phase by EDS spectra.