1998 Buick Century Don't works regulator of heating venilat

It sounds like you're talking about the heater fan and controls. If only the high speed works, the problem most likely is with the electrical resistors, which are on a cover plate bolted to the front of the heater box under the hood, near the fan. But if no speed works, the problem is most likely the fan itself. If you have a circuit tester, you can see if voltage is reaching the fan leads.