A capillary structure of vapor chamber and the vapor chamber. The capillary structure of vapor chamber includes a sintered main body. The sintered main body has multiple perforations and multiple extension sections integrally extending from one side of the sintered main body. The extension sections are arranged at intervals or not arranged at intervals to support the sintered main body. The vapor chamber includes a first plate body and a second plate body. The first and second plate bodies are correspondingly mated with each other to together define an airtight chamber. The second plate body has a heated section and a first capillary structure. The sintered main body is correspondingly disposed in the heated section and supported on (overlapped with) the first capillary structure. By means of the extension sections, the sintered main body and the first capillary structure define therebetween a gap.