The graduation thesis presents the influence of fire development on fire resistance of simple timber bearing elements according to SIST EN 1991-1-2 and SIST EN 1995-1-2. The fire analysis of timber bearing elements is divided into three phases. Parametric analysis of influence of certain parameters on fire development is performed in the first phase. On the basis of acquired results second phase follows in which, thermal analysis of timber elements is conducted. Here, charring depths for timber elements for every fire scenario are determined. In the third, last part of analysis, fire resistance of timber elements is determined. Parametric studies show that fire resistance of simple timber elements is mostly affected by chosen active fire protection systems, the maximum rate of heat release per square meter, number and size of openings in the object and lastly thermal absorptivity of sctructural assemblies. However, fire growth rate does not have any special influence on fire resistance of timber elements.