The applycation of microwave irradiation in the synthesis of heterocyclic compounds was reviewed through five sections: a) four member heterocycles b) five member heterocycles c) six member heterocycles d) seven member heterocycles and e) big heterocycles. Seventy one representative papers (1986～1999) were covered.

Key words: MICROWAVE TECHNIQUE, FOURMEMBER RING HETEROCYCLIC COMPOUNDS, SEVEN MEMBER RING HETEROCYCLICS COMPOUNDS, FIVE MEMBER RING HETEROCYCLIC COMPOUNDS, SIX MEMBER RING HETEROCYCLICS COMPOUNDS, HETEROCYCLIC COMPOUNDS, MACROCYCLIC COMPOUNDS, ORGANIC SYNTHESIS