Roman blinds are cloth blinds that pleat when they are raised. They provide a look in-between blinds and curtains, which can be elegant and modern in nearly any setting. The Roman blinds have little circles sewn into the fabric to hold the string in place. The string is attached to a simply pulley system. When you pull the string, the blinds should raise. If they don't raise, the string might be disconnected from the shade or the pulley. In some cases, in order to get the blinds to stay up, you have to tie a knot in the end of the string.
Examine the back of the Roman blinds. The string should go through every sewn-in circle on the back of the blinds. If the string is not in the circles, re-thread it through the circles to raise the blinds.
Sew the circles back onto the Roman blinds if they have come loose or fallen off. This can also cause the blinds not to rise.
Check the Roman blind's pulley system. The string should go up and over the pulley, so the blinds rise when pulled. If the string is not in the pulley mechanism, that could be the problem. Place the string back into the pulley and pull on the string the lift the blinds.
Tie a knot in the end of the string when the blinds are lifted. Make sure the knot is large enough that it will not slip through one of the circles in the blinds. This will keep the Roman blinds up.