In the first Opium War, the superficially flourishing Qing Empire was defeated by an island country from far away. Afterwards, the national power fell sharply and suffered repeated defeats.Faced with formidable enemies from the sea, Chinese navy fell short of knowledge, talents, technology and resources and the sea defense construction seemed more vulnerable.On the occasion of the crisis, ambitious persons strove to know and learn naval knowledge, employed foreign instructor counsel and built the fleet and sea defence facilities.During this period, they have undergone many unnecessary heartaches and spent a lot of money on lessons. All sorts of hardships have not disappeared in China until the 20th century and the arduous course become even more arduous.This book includes 17 articles and 18 authors from Hong Kong, mainland China and overseas historians, such as Ma Youyuan, Hou Jie, Lin Qiyan, Mai Jinsheng, Li Jinqiang, Zhao Yule and Qu Zhijian; it has carefully sorted out characters, knowledge, equipment and layout of the coastal defense in the late Qing Dynasty, deeply explored the history of the Kuomintang Navy at the end of Anti-Japanese War and faithfully recorded Hong Kong sea defense situation in the first half of 20th Century. It can be said that the whole book tells the experience, suffering and struggle of the Chinese coastal defense construction in modern times.