丝绸之路的起点是中国的古都长安，即今天的陕西省西安市。早在旧石器时代，原始先民就在今天的西安地区繁衍生息，留下了蓝田人遗址等多处遗迹。西周时期，都城镐京城址就在今西安市长安区西北的位置。而西汉王朝定都长安后，长安作为中国的政治、经济、文化中心长达千余年，先后有21个王朝和政权建都于此。在建都长安的诸多朝代中，汉朝、隋朝和唐朝都是中国历史上强盛的王朝，长安在汉唐时期已成为国际性大都市和世界上最大的都市之一。
　　西汉武帝时期丝绸之路开通后，长安城成为东西贸易的重要城市，盛极一时。城郭面积约36平方公里，大约是同时期罗马城的4倍，共有12座城门和8条主要街道。城内的宫殿集中在城市的中部和南部，居民区分布在城北，市场在城市的西北角上，称为“长安九市”。城西还有面积广大的皇家苑囿上林苑。各地的外销货物都集中在长安，再由各国商人把一捆捆的生丝、绸缎和其他商品用油漆麻布和皮革装裹后，组成浩浩荡荡的商队，从长安西行过咸阳，越过陕甘高原，经陇西、临洮、兰州、武威，穿过河西走廊，到达敦煌，再进一步运往中亚和西方。
　　唐代的长安城面积达84平方千米，是汉代长安城的2.4倍，比同时期的拜占庭王国都城大7倍。城内布局有如方整的棋盘，一座座外城墙将官城层层包围，重重殿宇金碧辉煌。笔直的街道，整齐划一的居民区，四通八达的供水网络，又体现了城市建设规划的周密全面。唐代的长安城是名副其实的国际大都市，据记载，当时来长安与唐通使的国家、地区多达300个。东罗马帝国曾先后7次遣使来长安，日本遗唐使抵长安约15次，阿拉伯帝国曾36次派使节到长安，西域各国“入居长安者近万家”。波斯人的珠宝店、西域人的酒肆，包括西方的良马、毛皮、玻璃器皿等在长安街市上均可见到。唐代人开放的心胸也使外来宗教得以进入中国。随着本土和外来宗教的兴盛，长安城中建起大量的佛寺、道观、波斯寺庙，对于不同的文化和信仰的包容，充分表现出这座城市及整个盛唐社会的自信和开放。
　　＞xi'an
　　The starting point of the Silk Road is China's ancient capital city-Chang'an,present day Xi'an,Sha'anxi Province.As early as in the Paleolithic Age,the original settlers thrived in today's Xi'an area,leaving many historical remains such as the Site of the Lantian Man.During the Western Zhou Dynasty,Haojing,the then capital city,was located in the northwest of today's Chang'an District of Xi'an City.After Western Han Dynasty was established,Chang'an was also designated the capital city and served as the political,economic and cultural center for more than a thousand years.In succession,twenty-one dynasties and regimes chose Chang'an as the capital.Among those dynasties,the Han,the Sui and the Tang dynasties are known as powerful and prosperous regimes in Chinese history.During the Han-Tang period,Chang'an became an international metropolis and one of the largest cities in the world.
　　With the opening of the Silk Road during the reign of Emperor Wu of the Western Han Dynasty,Chang'an City became the important city of East-West trade and enjoyed a period of booming prosperity in history.Covering an area of about thirty-six square kilometers and with twelve gates and eight major streets,the city was four times that of Rome over the same period.The imperial palaces were located mainly in the central and southern part of the city whereas the civilian residential areas occupied the northern part.The business area,consisting of〝nine markets"was concentrated in the northwest corner of the city.The western part of the city was a vast area of imperial gardens named Shanglin Garden.Export goods from around the country were first shipped to Chang'an where they were wrapped and packed by foreign merchants with painted linen and leather into bundles of raw silk,satin and other products and then shipped out by mighty foreign caravans from Chang'an westbound Xianyang,over the Shaanxi-Gansu Plateau,Longxi,Lintao,Lanzhou,Wuwei,through the Hexi Corridor,to arrive in Dunhuang,and then further transported to Central Asia and the West.
　　By Tang Dynasty the city proper of Chang'an expanded to eighty-four square kilometers,2.4 times that of the Han Dynasty,seven times larger than the capital city of Byzantine over the same period.The city layout was like a chess board,and the imperial palace was surrounded by rings of outer city walls.Inside the palace there were numerous splendid halls.The straight streets,the uniformed residential areas,and the efficient water supply network extending in all directions,all reflected the existence of a thorough and comprehensive urban master plan.Chang'an city during the Tang Dynasty indeed deserved the honor of an international metropolis.According to historical records,over three hundred countries and regions sent envoys to Chang'an for diplomatic connections.The Eastern Roman Empire sent their delegations to visit Chang'an seven times.Japanese delegations made about fifteen visits.The Arab Empire sent envoys thirty-six times to visit Chang'an.The number of households from the Western Regions lived in Chang'an reached ten thousand.Persian jewelry shops,Westerner-run taverns,western steed,fur,and glassware could all be found in Chang'an's markets.The open-mindedness of people of the Tang Dynasty enabled foreign religions to enter China.With the rise of native and exotic religions,a large number of Buddhism monasteries,Taoist temples and Persian mosques were built in the city.The inclusiveness of various cultures and beliefs fully demonstrated the self-confidence and openness of the city and the entire flourishing Tang society.