Abstract: Gas discharge tubes are commonly used as surge protection devices. In this paper, two different types of gas discharge tubes with the same static breakdown voltage, spark gap protector （SPG） and gas discharge tube (GDT), are chosen as research targets, whose responses subjected to the nanoseconds square pulse are compared. With the comparison results, certain rules for their practical application and parts selection are presented. The experimental results show that, for these two types of tubes, SPG has lower applied voltage under the same response time, while under the same applied voltage, SPG's response time is shorter. Above all, SPG has a better performance in nanosecond pulse protection than GDT does when the current is less than 3 kA. Considering its lower parasite capacitance, SPG is more suitable for the protection of antenna systems with high operating frequency.