In order to accelerate the detection efficiency of natural pigments stability， a new type of versatile and multi-conditions controlled apparatus for real-time kinetics based on online spectrophotometry was developed and applied to fading kinetic parameter determination of mulberry pigment with initial kinetic method， the effects of temperature， light and oxidant on stability were investigated. Results suggested that the apparatus was simple and extensibility， accurate and stable， applicable to automatic and unattended data acquisition of real-time kinetics of slow liquid homogeneous reaction process， especially for the stability monitoring of natural pigments. The color of mulberry pigments was related to pH values， and it presented bright red color at pH 3. Thermal， light irradiation and oxidative degradations of mulberry pigments followed first-order kinetics， the apparent activation energy of thermal degradation was 60.2 kJ/mol. High temperature， ultraviolet exposure and oxidant sped up the pigment degradation significantly. Low temperature， ultraviolet barrier package materials and a proper amount of VC showed protective effects.