How to go to Strasbourg by plane...
1. Simply flight direct to Strasbourg airport. This is usually the fastest, the easiest and often the cheapest. There is a regular train (every 15 min) from the airport which takes 10 min to the center of the city.
2. Flight to Paris (Roissy - Charles de Gaulle airport) and then take a train to Strasbourg. The train cost 60 to 100 euros (one-way) and takes 2h30min to reach Strasbourg. First class train tickets may be included in Air France flights. For more informations on the train visit the SNCF website.
3. Flight to Frankfurt airport in Germany and then take the Lufthansa bus to Strasbourg. The bus is either included in a Lufthansa ticket to Strasbourg station (XER) or you buy it seperately for 49 euros one-way. It takes 2h30 to reach Strasbourg. You can get more informations here. Alternatively, there are trains once per hour from Frankfurt airport.
Note that the Delta Air Lines website does not take into account all connections to Strasbourg. These can be found on the Air France site or with travel agents. These are the same aircrafts due to code sharing between Air France and Delta Air Lines.