As analysis on freefield pressure error and binaural pressure error in Ambisonics reproduction yields different results，and the results from binaural pressure error are closer to those of auditory perception． In this work，the influence of the number of loudspeakers on the pressure error in Ambisonics reproduction is evaluated by analyzing the binaural pressure error． The results indicate that，near the frequency limit given by Shannon-Nyquist spatial sample theorem，increasing the number of loudspeakers from low limit L2 to (L + 1)2 or (L + 2)2 reduces the error in reproduction effectively． Increasing the number of loudspeakers to more than (L +2)2 or increasing frequency to higher range，however，makes the relationship between the binaural pressure error and the number of loudspeaker complicated． The results of this work revise the conclusion of some previous work．