at night 是太阳下山以后约6点以后到12点之前；
in the evening是在傍晚,还看得到夕阳西下。
一、at night
1、音标： [æt nait]。
2、解释：夜间;在夜里;夜来。
3、造句：（1）It was late at night, and all was quiet in the village.夜深了，村子里沉静下来。
（2）The couple wed late at night in front of just nine guests.深夜这对情侣在仅有的9位宾客面前举行了婚礼。
（3）By day a woman could safely walk the streets, but at night the pavements became dangerous.白天的时候，妇女可以安全地在街上行走，而到了夜晚人行道上会变得很危险。
（4）It was late at night and he was still working away at his homework.夜深了，他还在做课外作业。
二、in the evening
1、音标： [in ðə ˈi:vniŋ]。
2、解释：在晚上。
3、造句：（1）In the evening we spruced ourselves up a bit and went out for dinner.到了晚上，我们稍微收拾打扮了一番，然后出去吃晚餐。
（2）When I'm going out in the evening I use the bike if I can rather than the car.我晚上要外出的时候，我宁愿骑自行车而不是开车。
（3）In the evening I returned to tell Phyllis our relationship was over.晚上我回来告诉菲莉丝我们之间完了。
（4）She didn't come back until very late in the evening.她直到晚上很晚才回来。