我国文字从古代的象形文字发展到今天的汉字，中间是经过多次变化和改革的；但是历代的改革几乎都是兼收并蓄的，以致使汉字越积越多。当前我国文字之多是非常惊人的,比较常用的《新华字典》就有10000多个汉字；1990年出版的《辞海》有14872个汉字；1716年编撰的《康熙字典》有47035个汉字；郭沫若生前曾根据日本朋友的估计,我国大约有60000多个汉字；1994年出版的《中华字海》有87019个汉字（其中重复字320个）；近来,根据北京国安资讯设备公司汉字库公布，共收入有出处的汉字91251个汉字。其中一级适用汉字21303个，包括国家标准提出的汉字、我国古今近1200个姓氏6699个汉字和当前乡村一级的地名专用字；二级适用汉字36581个，包括古今权威字典中音、义具全的汉字和十三经、二十四史等的古籍用字；三级备用汉字33367个，包括罕用字、异形字、音义未详字等。尚不包括杂书野史和各地地方志、名人笔记等自造汉字；还有正、草、隶、篆不同写法的异体字、同义字等。单据《说文解字》中就有别体字147个。有人估计实际汉字约在10万个以上；也有人估计在120000个以上；我国究竟有多少汉字至今尚没有定论。 ——copy from Baidu

Hello Montaser, It is until now not exactly known and a precise figure is not estimated. Throughout the dynasties there has been many dictionaries, where the number of characters varied from few thousands to around 50,000 characters. The later "Yitizi Zidian dictionary"of the year 2004 contains 106,230 thousand characters. However the knowledge of about 4000 character is enough to be able to read a newspaper and for all other purposes. Check the following wikipedian article for more info: http://en.wikipedia.org/wiki/Chinese_character#Number_of_Chinese_characters

There are over 80,000 Chinese characters in their language.

Lots.

No，now we use phrase more，but in ancient time，one character one meaning.