Broadband frequency property of chaos stands in the way of application. Internal parameter of a memristor leaves a new opportunity for easy amplitude/frequency control. Based on a variable-boostable chaotic system, such an amplitude-frequency controllable chaotic system is derived, which exhibits relatively robust chaotic oscillation compared with other multistable memristive systems. Furthermore, the controllable chaotic system gives a symmetric pair of oscillations, which finally merges to be a single symmetric one. Circuit experiment based on STM32 agrees well with the systematic analysis and numerical simulation.