SA's jobless rate fall in January

South Australia still has the nation's highest unemployment rate despite jobs growth, new data reveals.

SA's jobless rate dropped from 7.1 per cent to 6.8 per cent, bucking a rise in national unemployment, the Australian Bureau of Statistics says.

Employment Minister Kyam Maher says SA's unemployment rate has now fallen 1.1 percentage points so far this financial year - the biggest fall of any state.

But the opposition says it's not much to celebrate in the face of an 11.9 per cent underemployment rate, also the highest in the country, and the potential mothballing of Arrium's Whyalla steelworks.

Employment spokesman Corey Wingard has called on the government to extend the small business payroll tax rebate, which is set to be abolished in July.