You may need a new bottom bracket.
The crank you choose determines the bottom bracket you need. Each crank requires a specific interface (splined, ISO square taper, JIS square taper, etc) and spindle length.
If your new crank takes the same interface and spindle length as your old crank, you can use the same bottom bracket (assuming it's in good shape). If either the interface or length is different for the new crank, you will need a new bb.