In May 1863，The King of Vietnam Tu Duc ordered the court Highest Officer Phan Thanh Gian（潘清简） as the official envoy leading nearly thirty members to visit France and Spain negotiation to redeem Southern three provinces. After Phan Thanh Gian returned to Vietnam in February 1864，he collected the records of his colleagues and wrote the book Xifu Diary （《西浮日记》）and presented it to Emperor Tu Duc. The book recorded what he saw during the journey，including the number of miles，the position of the rudder，the direction of the wind and the waves，and the names of the islands，nations，harbors etc. Since the book was recorded in Chinese，but in 1863-4，there was no unified Chinese translation for place names everywhere in the world，so it is not easy to interpret the place names of the land and sea journeys. This article’s purpose would use the Google Map GPS to interpret the place names and ports or places of that voyage one by one based on the sight of map，pronunciation，azimuth，and navigation path，and mark it with the current name，so that readers can recognize the place when the steamship that passing through. When Phan Thanh Gian returned to Hue in February 1864. The Court did not agree with the results of the negotiations，the French army invaded and occupied the six provinces of South Vietnam in 1867. Phan Thanh Gian died on a hunger strike，martyring his country.