This article studies the influence of the non‐tradable share reform in the cross‐section of stock returns in China. Prior research has generally neglected this important development in the Chinese stock market. We find that the firm‐specific illiquidity measures that reflect direct transaction costs, price impact and difficulties in trading immediacy, exhibit a positive and significant relationship with stock returns. These effects are particularly pronounced after the non‐tradable share reform. Furthermore, in the post‐reform era, portfolios with high illiquidity (i.e. high relative bid–ask spread, high Amihud illiquidity, low Amivest liquidity ratio) significantly outperform portfolios with low illiquidity, controlling for size, and book‐to‐market effects.