[caki]

How to stable KClO3?
Maybe Barium?

Thanks

[Arkcon]

This question, as asked, is unanswerable.  We need more context.  Potassium chlorate is perfectly stable, as a dry solid, or in solution in water.  Presumably, you're talking about its powerful oxidation tendencies, but you don't mention what you're reacting it with.  Perhaps you mean its decomposition when heated.  So what?  Don't heat it.  You mention barium.  Again, so?  Elemental barium?  Do you want to convert it to barium chlorate?  Do you want to add barium oxide as a refractory to dull potassium chlorate's deflagration? 

Please be aware of this forum's rules -- we don't give tips or detailed plans for explosives manufacture.  And we don't give explicit instructions on complex, dangerous procedures to complete amateurs.  You will have to impress us more with your knowledge and give a better explanation of what you need to get an answer.