Post suspension composite insulator for Railway is consisting of ECR fiber-glass core and silicone rubber housing with sheds and end fitting. The insulation part is consisting of housing and  sheds which injecting outside of core. The end fittings is crimped with ECR fiber-glass core to be easy to connect with hardware fitting of T/L.; The end fitting could be bear mechanical load with fiber-glass core and at the same time the fiber-glass could provide the inner insulation; silicon rubber is provide excellent hydrophobic property, anti-aging and chemical stability, the silicon rubber which covered core protect it avoiding corrosion to be sure the excellent inner insulation property, further more the silicon rubber housing with sheds could provide the prefect electrical property.