[Solved]-Highcharts highlight single point on line-Highcharts

Using a marker we can do this:

$(function () {
    $('#container').highcharts({
        chart: {
        },
        xAxis: {
            categories: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']
        },



        series: [{
            data: [29.9, { marker: {
                    fillColor: '#FF0000',
                    lineWidth: 3,
                    lineColor: "#FF0000" // inherit from series
            },y:71.5}, 106.4, 129.2, 144.0, 176.0, 135.6, 148.5, 216.4, 194.1, 95.6, 54.4]        
        }]
    });
});

http://jsfiddle.net/zR4Kn/