In the 4th century the Roman Catholic Church chose December 25 as the day for the Feast of the Nativity （耶穌誕辰） . The church chose December 25 for a Christian holy day in the hope of giving Christian meaning to existing pagan celebrations of the winter solstice （冬至） . As a result, many pagan customs gradually became part of the Christmas celebration.
By the 12th century, Christmas had become the most important religious festival in Europe. In the 19th century, two Christmas customs became popular － decorating Christmas trees and sending Christmas cards to relatives and friends. Many well-known Christmas carols were composed during this period.
For most people who celebrate Christmas, the holiday season is an occasion for gatherings （聚會） of family and friends, feasting, and giving gifts. The celebration of Christmas became increasingly important to many kinds of businesses.
One of the most important Christmas traditions is receiving gifts from Santa Claus. Many young children believe that the presents they receive at Christmas are given by Santa Claus, who is a jolly, white-bearded fat man in a red suit and red hat. According to the story, Santa Claus travels through the air from somewhere near the North Pole in a sled drawn by reindeer （馴鹿） and comes down the chimney （煙囪） to leave the presents. Today, Santa Claus brings presents to children in many countries, including the United States, Canada, Great Britain and Australia. Many department stores hire people to wear a Santa Claus costume and listen to children's requests. In Great Britain Santa Claus is also called Father Christmas. During the weeks before Christmas, children write letters to Father Christmas and tell him what presents they would like to receive. They then throw these letters into the fire. Children believe that if a draft draws the letter up through the chimney, their wishes will be fulfilled.
A traditional Christmas dinner in America includes stuffed turkey （火雞） , mashed potatoes, cranberry sauce （越橘醬） , and a variety of other dishes. Roast turkey is the most popular main course not only in the United States, but also in Canada, Australia, and New Zealand. Some families have ham or roast goose instead of turkey. Favorite desserts include mince pie or pumpkin pie, plum pudding （李子布丁） and fruitcake. Eggnog （蛋奶酒） is a popular Christmas beverage （飲料） in many homes. In Britain, Christmas dinner is eaten at noon, and the dinner usually includes roast turkey or goose, Christmas pudding with mince pies, and accompanied by wine.
聖誕節是個基督教節日，慶祝耶穌基督誕生。英文“ Christmas ”壹詞源於古英語的“ Cristes maesse ”，意思是基督的彌撒，或基督的節日。至於頻繁使用的聖誕節的簡寫形式“ Xmas ”，學者們認為也許是始於 13 世紀。在希臘語裏，“ X ”是“基督”的首字母，同時“ X ”也象征耶穌受難的十字架。
公元 4 世紀，羅馬天主教會將耶穌的誕辰定在 12 月 25 日。教會將 12 月 25 日定為基督教節日是為了給當時異教的冬至慶祝活動註入基督教的含義。結果，很多異教習俗逐漸融入聖誕節的慶祝活動。
到了 12 世紀，聖誕節已成為歐洲最重要的宗教節日。 19 世紀，兩個聖誕節習俗，即裝飾聖誕樹和向親友贈送聖誕卡，變得流行起來。許多著名的聖誕頌歌也是在這壹時期創作的。
對於大多數過聖誕節的人來說，這個節日是家庭、朋友聚會的日子，享用美酒佳肴的日子，互贈禮物的日子。聖誕節的慶祝活動對許多工商企業也變得日益重要了。
聖誕節的重要傳統之壹是接受聖誕老人贈送的禮物。許多小孩子相信自己在聖誕節收到的禮物來自聖誕老人。聖誕老人是個快活的胖老頭兒，長著白胡子，身穿紅 袍，頭戴紅帽。據說聖誕老人從北極附近的某地出發，駕著馴鹿拉的雪橇從空中飛到各家，從煙囪進入屋內，留下禮物。現在，許多國家，包括美國、加拿大、英國 和澳大利亞，都有聖誕老人把節日禮物送給孩子們。許多商店雇人裝扮成聖誕老人，傾聽孩子們的願望。在英國，聖誕老人也叫“ Father Christmas ”。聖誕節前幾周，孩子們就開始寫信給聖誕老人，告訴他自己想要什麽禮物。然後他們把信扔進壁爐的火裏。他們相信，如果上升的氣流把灰燼順煙囪帶了上去， 他們的願望便會得到滿足。
在美國，聖誕節宴席上的傳統食物有填餡的火雞、土豆泥、越橘醬等。烤火雞不但在美國，在加拿大、澳大利亞和新西蘭也是聖誕宴席上最普遍的主菜。也有的人家 不吃火雞，而吃火腿或烤鵝。人們最喜歡的飯後甜點包括甜餡餅或南瓜餡餅、李子布丁和水果蛋糕。蛋奶酒是許多家庭喜歡的飲料。在英國，聖誕宴在中午舉行，傳 統食品有烤火雞或烤鵝、聖誕布丁、甜餡餅和葡萄酒。