For the practical use, it is very important to know basics about fire-technical characteristics of wood which also include the flash point and ignition temperature. Diploma thesis describes macroscopic and microscopic features, chemical structure of wood and physical properties of coniferous and deciduous trees. This thesis summarizes knowledge about combustion while focusing on process of combustion initiation. Our work is based on a literature research. This research helps us to make an overview of published results about the assessment of fire technical characteristics of coniferous and deciduous trees characterizing initiation of combustion. It also helps us to identify dominant factors of trees and environment which affect the flash point and ignition temperature. Fire technical characteristics of wood are improved by using flame retardant which prevent ignition and spread of fire.