This paper examines the effect of Chinese macroeconomic variables, the industrial production growth rate, the producer price index, the 3-month short-term Shanghai Interbank Offer Rate and the consumer price index, on the volatility of the Shanghai and Hong Kong stock markets. We apply the generalized autoregressive conditional heteroskedastic mixed data sampling model for the study. Our empirical findings on various indexes and enterprises in the Shanghai and Hong Kong markets show that Chinese macroeconomic variables have a greater power to explain the volatility in Hong Kong than in Shanghai. They also contribute significantly to Hong Kong’s market volatility.