Electrocatalyst for water electrolyser is one of the promising research fields for various renewable energy applications due to current energy problem. Although recent advances in developing efficient electrocatalysts have been achieved by various strategies including alloy, doping and shape control, there still remain large gaps to be resolved. To address these issues, fundamental understanding of functional links between activity and durability is timely urgent. In this talk, discussions on the activity and durability trend of transition metal based hydr(oxy)oxide electrocatalyst in alkaline media will be covered. Based on the fundamental understanding of functional relationship, effective material design strategies for durable and active electrocatalyst and discussion the role of each design principles for durability enhancement will be presented.