What should I do if my baby will not take a bottle?

Cup. Many breast fed babies will not take a bottle. This is a challenge. For those who really will not take a bottle at all, then work with a sippie cup and practice practice practice. By nine months many children can actually drink form a straw..The small juice box size straws. It seems logical from your question that you are breastfeeding. If there is more that is a concern, discuss it with your md.
Bottle feeding. Don't force it. Slowly introduce the bottle when the baby is happier, possibly after a nap. It could also be your choice of nipple that the child is unable to latch on to. Trial and error will be best.

Related Questions

What should I do if my baby will not take the bottle?

Bottle aversion . (1) make sure you are using the correct nipple with right amount of flow. (2) hold the bottle correctly (3) sometimes negative pressure in the bottle would increase baby's sucking effort (4) lastly you may have to consult an occupational therapist who specializes in these problems. Read more...
Keep trying. Introduce the bottle around 3 weeks of age, once breastfeeding is established. Use a slow flow nipple at first and move up to a faster flow if your baby tolerates. Warm the milk or formula (not in microwave!) and try different positions. Some babies like to be held in a breastfeeding position and others like to be sitting up straighter. Experiment and see what your baby likes. Read more...
Have dad try. To avoid a baby who will only eat from the breast start using a bottle every other day when the baby is about 1 month old. When using a bottle have dad feed him when mom's out of the house (seeing and hearing mom means the breast is an option). Try the bottle when he's hungry but not famished or when he's sleepy. Try different positions or movements to distract him. Warm the milk and the nipple. Read more...