Abstract: In live  streaming commerce, the streamer group is the core factor that drives product's sales performance. This study aims  to understand  how  the  combinations  of streamers  volume, product's  line  breadth, and brand  type  influence  brands'sales performances in live streaming commerce. The study collected panel data on Douyin live streaming platform in an 18-week period from August to December 2020 of 17 luxury brands and 27 non-luxury brands that are representatives of the cosmetics industry, which  includes  261  streamers, 1,658 products and  3,119  live  broadcasts. We  used  a  two-way  fixed  effects  model  with STATA software, and  found  that  streamer  volume  has  a significant  inverted  U-shaped  impact  on brands' live  sales, and  the breadth  of product's  line  has  a  significantly  direct positive  impact  on  brands' live  sales. Besides, product's  line  breadth and brand type moderate the above inverted U-shaped effect.

Key words: streamers volume; brand; product line; live , streaming commerce, sales performance