In this paper, chromosome numbers of 14 species of the genus Amaranthus from China are reported: A. retroflexus 2n=34, A. caudatus 2n=32, A. hybridus 2n=32, A. spinosus 2n =34, A. cruentus 2n=34, A. hypochendriacus 2n=32, A. paniculdatus 2n=32, A. roxburghianus 2n=34, A. blitoides 2n=32, A. polygonoides 2n=34, A. albus 2n=32, A. viridis 2n = 34, A. lividus 2n = 34, A. tricolor 2n = 34. The number in A. roxburghianus is reported here for the first time. The basic chromosome numbers in this genus are x = 16 and x = 17 and both numbers are found in sect. Amaranthus and sect. Blitopsis. The chromosomes in this genus are very small in size, hampering a detailed karyotype analysis.