The chemical modification of 1,4-polydienes by dialkyl (or aryl) phosphates was considered in order to improve their flame-resistance. Chemical introduction of phosphorus onto polydienes was carried out by a two-step process : partial epoxidation of unsaturated units and introduction of the dialkyl (or aryl) phosphate using the reactivity of the P-OH acidic bond towards oxirane rings of epoxidised 1,4-polydienes (synthetic polybutadiene, polyisoprene and liquid natural rubber). Incorporation of phosphprus (around 1.1-1.2 weight percent) in crosslinked polydienes is generally sufficient to produce air fire-resistant materials. The best limiting oxygen indices (LOI) are obtained with diphenyl phosphate. Degradation kinetics of modified polydiene networks at moderate temperatures (from 200 C to 400 C) are more and less similar to those of unmodified specimens but the weight losses are weaker after 400 C. The residual masses after 600 C are relatively important compared to the unmodified specimens which are entirely decomposed at this temperatue.