区别：
一、逻辑不同
led to 和lead to 的区别是前者是后者的过去式。
led是lead的过去分词，他们的用法是相同的。
二、含义不同
led to:导致
1、This hard attitude may have led to his undoing.
可能就是这种强硬的态度导致了他的垮台。
2、Smoking can lead to lung cancer.
抽烟可能导致肺癌。
lead to:导致，引起；通向；把…带到
1、The Government's present course will only lead to disaster.
政府的现行方针后患无穷。
2、Too much work and too little rest often lead to illness.
过量的工作和过少的休息会引起疾病。
3、Such an offence will lead to a summary fine.
这类过错要当场予以罚款。
4、Excessive patriotism can lead to xenophobia.
爱国主义过了头即可导致仇视一切外国人。
5、A full-scale nuclear war could lead to the annihilation of the human race.
全面的核子战争能导致人类的灭绝。
6、All roads lead to Rome.
条条大道通罗马。
三、语法不同
lead sb to do sth通常表示使（导致）某人做某事（有时含有误导之意）。如：
He led me to believe that he had a lot of influence. 他让我相信他很有影响力。
Her constant lying led me to distrust everything she said. 他经常撒谎，我完全不相信她的话了。
还可以lead sb to sth（其中的sth具有动作意味）。如：
What led you to this conclusion? 你是怎么得出这个结论的?
一、led to 是lead to 的区别是前者是后者的过去式。
二、因为led是lead的过去分词，所以，他们的用法是相同的。
三、例句：
1、led to：导致
（1）、Reforms have led to the saturation of the market with goods. 改革已经使得市场上商品饱和。
（2）、This thesis led to a radical reshaping of Labour policies. 这篇论文导致了工党政策的彻底改变。
2、lead to：导致，引起；通向；把…带到
（1）、The Government's present course will only lead to disaster.政府的现行方针后患无穷。
（2）、Too much work and too little rest often lead to illness.过量的工作和过少的休息会引起疾病。
本回答被网友采纳the
game引导主语从句；
2.用led
to是因为本句是举例子(存在这样的现象)，用lead
to的过去式。