Durability test of emission control system for a China Ⅳ diesel engine is operated on an AVL engine test bed. European steady state cycle(ESC)test and European transient state cycle(ETC)test are both conducted before and after durability test. The emissions are measured by AVL AMA i60 Exhaust Measurement System. The emission characteristics of gaseous pollutions measured before durability test shows a behavior similar to the ones after durability test at the engine operation conditions. After the Durability test, NOx emissions show minor change, emissions of PM, CO and HC are increased up to 67%, 508% and 85% respectively in ETC cycle, whereas they increased slightly in ESC test. The diesel engine can meet the China Ⅳ emission standard during the durability test, and the emission control system complies with the national standard GB 20890-2007.