Single-crystalline erbium chloride silicates have attracted extensive attention due to their high gain compatibility and silicon compatible properties. Long-lived near-infrared fluorescence is critical for reducing a pump density threshold when erbium containing materials are used as active devices. Here we developed a single-source chemical vapor deposition (CVD) method to grow high-quality single-crystalline erbium chloride silicate nanostructures. The growth mechanism is found composing of two steps, where silicon source comes from the minor evaporation of silicon substrate. The prepared single-crystalline erbium chloride silicate nanowires own diameter of about 200 nm with few lattice defects, and the fluorescence lifetime reaches up to 7.4 ms. A nanoscale thermometer based on their visible band fluorescence is realized.