var str = "121.651778519457, 31.335598193999 121.651677477117,31.3356535990687"; var split = '([\\s\\S]*?)'; var reg = new RegExp('121\\.\\d+'+split+'31\\.\\d+','g'); // console.log(str.match(reg)); var list=[]; while( res = reg.exec(str)) { list.push(res[0].replace(res[1]," ")); } var formated=list.join(",") console.log(formated);