This article is an overview of the press release of the Be Vigilant against Danger：World Socialism Series co-sponsored by the World Socialism Research Center and the Social Sciences Academic Press of the Chinese Academy of Social Sciences. The 10-part series received favorable comments from the participants：it presents a broad view of the magnificent and tortuous history of world socialist movements in the 20^th century；it follows a distinct theme and reviews the history when different schools of thought clashed and mingled with each other；it provides an incisive analysis of the history when pioneers blazed the trail and made it through socialist movements；and it sounds an alarm on the erroneous trends of thought that have potential harm to Chinese socialism，demonstrating the Marxists’ firm conviction in building socialism with Chinese characteristics.