Abstract: Reed Solomon (RS) codes,which have been adopted by several international standards,have found increasing application in such areas as satellite and mobile communications,data storage and transmission,video systems,etc.The development of efficient encoding scheme is thus of great importance especially for high speed applications. The dual basis is considered as the suitable basis for the RS encoder to operate over.This paper is concerned with the RS encoder over the extended dual basis.First,the method of obtaining the optimal dual basis is introduced and the optimal dual basis is calculated for the CCSDS RS code.Then,instead of the bit serial encoder,a bit parallel dual basis RS encoder is designed for high speed applications.The proposed RS encoder has the advantages of high throughput,low hardware requirements and is suitable for VLSI implementation.