When I use China clay for making things, it is good, but when it is dry, after some time, they end up broken. Can anyone tell me that what can I do to prevent my works from breaking during the drying process?
China clay is or kaolin is not structurally strong enough just on its own and needs to be mixed with other materials to form a more robust material that will survive the pre-firing drying period. Assuming this is happening pre-kiln. When you say " when it is dry after some time they end up broken" it sounds like you may not be firing them soon enough or not at all, which is required for them to remain solid. Otherwise they will return to the dust that they came from.
It could be that your clay is not plastic enough. Meaning the elasticity of the clay. Once way to improve the elasticity is to age the clay with mold fungus. You can do this by adding beer or milk to the clay, mix it in and let it sit covered over a period of time. Fungus has microscopic fibers that help bind the clay and water molecules together.