Abstract: In order to offer evidence for high yield cultivation and selecting new varieties, different treatments of planting density sowing date and fertilizer application dose were selected to treated four main highland barley in Tibet, a field experiment was conducted to study the grain filling processes of different varieties. The results showed that, in different treatments of planting density sowing date and fertilizer application dose, the Grain-filling Characteristics of different highland barley Varieties exhibits a similarity, and the size of average filling rate to four highland barley were respectively 'Zangqing2000'＞'Zangqing320'＞'Ximalaya22'＞'Zangqing13'. The effects of planting density sowing date and fertilizer application dose to grain yield was in sequence of sowing date＞fertilizer application dose＞planting density. The dry weight of one hundred seeds at whole filling stage were all between 3.54 g and 6.71 g, the highest average dry weight of one hundred seeds was 'Zangqing2000' with T1 treatment (sowing date 20th April), reached to 5.8 g. The results of these studies indicated that sowing date is the most significant cultivation factor to grain-filling characteristics and production benefit of highland barley. So, early sowing at an appropriate time is the key factor for highland barley to obtain high yields.