[Solved]-How to show gridlines only on 0 on the yAxis in highcharts?-Highcharts

You can set gridLineWidth as 0. http://api.highcharts.com/highcharts#xAxis.gridLineWidth

Example: http://jsfiddle.net/ssQVJ/

yAxis: {
        gridLineColor: '#197F07',
        gridLineWidth: 0,
        lineWidth:1,
         plotLines: [{
            color: '#FF0000',
            width: 1,
            value: 0
        }]
    },