An accessorizable security camera has at least one functional accessory and a camera body having a case, security camera optoelectronical module, a front cap assembly and a rear cap. The case is tubular and has a front opening, a rear opening, an outer surface and at least one guiding structure. The at least one guiding structure may be a recess being formed longitudinally on the outer surface of the case. The at least one functional accessory may be a weather cover, an auxiliary light source, an auxiliary mounting bracket, a motion sensor, a combination thereof or the like. The at least one functional accessory has a mounting structure corresponding to the guiding structure and being selectively and detachably mounted in the guiding structure. Therefore, the at least one functional accessory may be easily mounted on the camera body by using the mounting structure to increase flexibility of use.