【Objective】To evaluate the safety and efficacy of Guidezilla extension catheter of complex coronary intervention.【Methods】This was a retrospective study and 72 patients with complex coronaryartery diseases were enrolled during August of 2015 to September of 2017. The Guidezilla extending catheter was used during percutaneous coronary intervention（PCI）and the successful rate and the incidence of complications were recorded. In addition，the adverse cardiovascular events were also recorded during follow-up.【Results】The overall successful rate of PCI with the Guidezilla extending catheter was98.6%. One case was failure due to the stent was stripped of fitsballoon. None of the patient sexperienced coronary dissection，perforation，air embolism，pressure dampening or other major complications during theprocedure. Among these cases，there were 4 chroni ctotal occlusion lesions，44 calcified lesions and 30 tortuous lesions. Sixtyfive cases were performed by radial access. After 1 month’s follow-up，none of the patients had any adverse cardiovascular events occurred.【Conclusion】During PCI procedure，the application of Guidezilla extension catheter for the treatment of complex coronary anatomy appeared safe and efficacious.