The chitosan derivatives(S-CTS and RS-CTS) were prepared and the application of the derivatives in surface activation process for Ni electroless plating was exploited. S-CTS was prepared by shiff-base reaction of CTS with salicylic aldehyde and RS-CTS was prepared by reduction reaction of S-CTS with KBH4. The results of FT-IR spectroscopic characterization showing the formation of C＝N in S-CTS and C－N in RS-CTS indicated that the above reactions occurred in the supposed route. The thermal properties of the derivatives were studied by Thermogravimetry-Differential thermal analysis (TG-DTA) methods. It is suggested that the thermal stabilities of CTS derivatives were better than that of CTS. Furthermore, RS-CTS is capable of forming even films on ABS surface and adsorbing adequate Ni nano-catalysts for follow-up electroless plating. Optic tight and dense plating layers were finally obtained. It is showed that RS-CTS could be applied as a biopolymer film in activation process for electroless plating.