I am writing this letter for the purpose of inviting you to take part in the party/celebration/conference...which will be held in ... on ... It would be great honor for me if you could participate
I am writing this letter to invite to you to visit ...I do hope we can have a chance/opportunity to meet each other again.It would be great honor for me if you could come
集体类：（代表一个集体：公司/班级/机构）
on behalf of our depatment/company...,I am writing to invite you to give a lecture/take part in /participate in /attend the reception(conference/part/ceremony)which will be in .....(Xi'an)on......(August 12th)
第二段
第一句：邀请对方的原因/举办活动的目的
私人类：
You are one of my closet friend and we have departed for a long time.If you could come,I can have a chance to refresh our friendship and pay back your hospitality (我有机会重温我们的友谊，报答你的盛情款待)
集体类：
For your prestige in this fied,we disire that you could deliver a speech for our staff/students on ......(environmental pollution) and answer some questions they put forward after the speech(你是这方面另领域专家，我们热切希望你能分享关于环保的问题给我的员工或学生，同时在演讲后可以提出一些问题)
第二句：邀请活动具体的地点（不同于第一段的表达）
This activity /party/celebration/conference/reception will be held in +地点（Guomao hotel in Beijin）
第三句：邀请活动具体的时间（不同于第一段的表达）
This activity /party/celebration/conference/reception will be started/lauched at+时间（six o'clock on Saturday,August 12th./from .... to...）
第四局：邀请活动的其他信息
私人类
It is universally acknowledge/known that my hometown is a beautiful/an ancient city with many famous tourist attrctions/historical sites worth visiting(众所周知，我的家乡是一座古城，有许多著名的旅游古迹值得一游)
集体类：
The president of our school and most of the teachers will also join us./The manager of our company and most of the staff will also join us.(我们学校的校长和大多数老师也将参加我们的活动。/我们公司的经理和大多数员工也将加入我们。)
第三段
第一句：首尾呼应，再次邀请
We would be appreciated/grateful very much if you could accept the invitation
第二句：期待你的回信
If you have any questions ,please feel free to contact me directly.Looking forward to your reply(私人类)
I would be very appreciated if you give me a reply within two weeks.I would provide more information for you.
