Long noncoding RNA (lncRNA) is a transcription by-product of RNA polymerase II, comprising more than 200 nucleotide in the absence of the ability to encode proteins. In recent years, more and more studies have found that lncRNA can be involved in the occurrence and development of diabetes, cardiovascular diseases, and a variety of degenerative diseases by regulating cell proliferation, differentiation, and apoptosis. As the first identified lncRNA molecule, H19 has been found to interfere with glucose and lipid metabolism balance, and is closely related to Type Ⅱ diabetes mellitus (T2DM) and its complications, making it a new hot spot in T2DM research. The review introduced identified targets of H19 involved in the process of T2DM and its complications, briefly described the functions and related molecular mechanisms of H19, and proposed future research directions.