一，两者都是介词短语词组，只是“in search of”较常用一些罢了。语法学家Shaw早在1970年就曾指出：“in search for is also common，but in search of is preferred.”(“in search for也是通用的，但是in search of则更好”)。举例：
1．…while in search for a title for his first book of poems．……在他寻找他的第一部诗集的书名时。
2．…not the businessman in search for orders or for the secrets of know-how．……不是寻找订单或技术秘密的商人。
二，In search for可以这么用，但一般会在search前面加个反身代词。
相当于：
in search of (=in one's search for)
为了寻找, 追求
三，search for look for 指的是动作的过程 不指明是否找到某物
但是Find search out 都表示一个短暂性动作（而非过程）并且含有找到某物的意思 search 相关短语：
Advanced Search 高级搜索
building search path n.建立搜索路径
conduct a search through 在…中搜索
Delete Search 删除搜索
in a search for 为寻找,在寻找的时候
in one's search for 为了寻求…
in search of adv.寻找
in search of romance 寻找奇遇
in the search for 在寻求…时,为寻找
job search 找工作
search out的例句：
He who would search for pearls must dive below
欲寻珍珠,须潜水下He who would search pearls dive deep
不潜深水采不到珍珠"Errors, like straws, upon the surface flow; he who would search for pearls must dive below"
错误像稻草,漂浮在水面欲觅珍珠者,须往水下潜He was rifling through her desk in a desperate search for the letter.
他拼命在她的书桌里搜寻那封信。A flock of sheep ranged over the mountain slope in search of pasture
一群羊走遍了山坡找寻牧草。
