In parallel processing of the Kohonen``s self-organizing algorithm, the only bottleneck is to determine the "global winning cell" after finding the "local winning cell" in the processors. According to the communication topologies to determine the global winning cell, two parallel algorithms are shown in a multiprocessor computer implemented on common bus. The efficiency of the processor utilization is above 97\% when we employ 800 neurons for 2-D coordinates mapping of Kohonen``s algorithm using 8 processors.