i will be coming to Pudong airport on 12th of may and i want to go to a Zhangjiagang , how to go??

From the airport, there are direct buses to reach Zhangjiagang directly. The time table is 11:40, 12:50, 14:40, 15:40, 17:40 and 19:40,
If you cannot catch those buses, you can take the airport shuttle bus line 5 to reach local railway station where you can find the SH General Long-distance Bus Station. At this station, you can frequent buses to reach Zhangjiagang.