This study aimed to examine the effect of the Corporate Social Responsibility disclosure on stock prices and find out if the firmâs size is able to be variable moderating the influence of CSR disclosure to the stock price. The study was conducted at a mining companies listed on the Indonesia Stock Exchange 2011-2013. The samples using purposive sampling and obtained a sample of 10 companies with annual report data during 2011-2013 were 30 reports. Data analysis used the difference absolute value. The test results show that corporate social responsibility disclosure has significant positive effect on stock prices. The testing of difference absolute value shows that the firmâs size is not a moderating variable to influence corporate social responsibility disclosure to the stock price.Keywords: Corporate Social Responsibility (CSR), stock price, firmâs size, test of absolute difference value.