Three electronic vehicle China companies have developed rapidly in recent years. But they have totally different beta according to the average data of past five years. The beta of Li auto, NIO and XPeng is 0.63,1.85,2.85. Therefore, we analyze from the perspectives of policy, market, research and development and sustainable development to discover the reason behind the beta difference and industry characteristics. Since three companies are all listed, therefore, we make full use of the annual report and publicly disclosed information. After comparison, we find that Li has the lowest beta due to its small category but with a single explosive product, high sales growth and market share, electricity-oil mixed long endurance capability and low percentage of R&D cost. While NIO list medium due to its product variety but quite low endurance, medium sales growth and market share, huge power swap station but fixed cost involved and medium R&D expenditure. Finally, XPeng has the highest beta due to its wide price range, comparatively slow growth rate and market share, first one to conduct oversea market trials and large R&D cost.