Abstract: The cause of the formation of spalted wood has long believed to be the fungus secreting melanin. This article reviews the formation mechanism and formation conditions of spalted wood (including wood species, main fungal species and influencing factors). Based on our recent findings, the wood grain is located in the heartwood part of some trees, and there is no rot and fungus. The grain runs through the whole trunk. This has led to a new direction of 'Bacteria Type Spalted Wood'. The new direction is expected to effectively control decay and promote the formation of spalted wood, and promote the production of high value-added wood and wood crafts.