The　oxidation　characteristics　of　Ge-modified　silicide　coating　on　the　Nb-Si　based　alloy　within　the　moderate　temperatures　were　investigated.　Results　show　that　the　mass　gains　of　the　coated　alloys　are　0.41,　0.58　and　0.37　mg/cm(2)　after　oxidation　at　700　degrees　C,　750　degrees　C　and　800　degrees　C　for　100　h.　There　is　no　pest　phenomenon　at　the　test　temperatures.　The　oxide　scale　is　composed　of　amorphous　aluminosilica　and　SiO2-GeO2　with　TiO2　dispersed　in　some　of　SiO2-GeO2.　The　good　oxidation　resistance　of　the　Ge-modified　silicide　coating　at　moderate　temperatures　is　attributed　to　the　selective　oxidation　of　Ti　and　Si,　as　well　as　the　formation　of　glassy　SiO2-GeO2.