光子晶體是一種介電質週期性排列的人為設計元件，可經由不同的設計成為波導或是共振腔。其中二維光子晶體共振腔在近十年來有重大的突破與發展，從最簡單的H1 共振腔到Q 值被證實高達45000 的L3 共振腔都引起許多研究者的高度興趣。本論文即著手研究H1 與L3 共振腔的共振模態，藉由共振腔的調變瞭解兩者之間有何關連性存在。由理論分析與量測實驗的對應比較，掌握了各個模態的行為特性，也對Q 值的變化有了更深入的瞭解。 Photonic crystal is an artificial device which arranges its dielectric material periodically. We can fabricate it as a wave guide or cavity via different design ideas. Two- dimension photonic crystals had significant development in recently decade. Numerous researchers were interested in H1 cavities and L3 cavities which were demonstrated possessing high quality factor as 45000. My thesis investigates resonance modes of H1 cavities and L3 cavities. Via adjusting the geometry structures of these cavities, we can understand the correlation of cavity modes between H1 and L3 cavities. Comparing theory analysis and measurement experiment, we can know well about behaviors of these cavity modes. Furthermore, we realize the variation of quality factor more deeply.