you must visit Tianjin great roads. There are many beautiful building there.Aad it has many history story.

3 days is enough for TianJin city.
1.GUWENHUA street
2.HAIＨＥ
3.NANShi food street
4.DABEIYUAN(temple)
For shopping,you can go to BINJIAN street.

Take a day trip to the Great Wall at Yellow Pass. NOT CROWDED there. Shopping includes Binjiang Dao, the pedestrian street in the centre of town. Want bargains?? Markets?? Go to Da Hu Tong. Not too far from the centre of the city. There is a light rail (30 minutes) that goes to Tanggu, the port city of Tianjin Municipality. There is a big market there. In fact, the saying is....if it's not in Tanggu Markets, then it doesn't exist!!! Lots of fakes though, so beware. If you like the fakes, you can get Rolexes for Y30-50 ($US5-$US7). Bargain like mad. Get animated. Walk away and make them bring you back!!
Another day, you can check out the Wuda Dao neighbourhood, or Ancient Culture Street.