css：

    #headermenu {
    /*outline: 1px solid red;*/
}
#headermenu ul {

}
#headermenu ul ul {
    display: none;
}

    #headermenu ul li:hover > ul {
        display:inline-block;
    }
#headermenu ul {
    background: #f69b58; 
    /*background: linear-gradient(top, #efefef 0%, #bbbbbb 100%);  
    background: -moz-linear-gradient(top, #efefef 0%, #bbbbbb 100%); 
    background: -webkit-linear-gradient(top, #efefef 0%,#bbbbbb 100%); 
    box-shadow: 0px 0px 9px rgba(0,0,0,0.15);*/
    padding: 0 20.05px;
    list-style: none;
    position: relative;
    display: inline-block;
}
    #headermenu ul:after {
        content: ""; 
        clear: both; 
        display: block;
    }   

    #headermenu ul li {
        float: left;
    }
    #headermenu ul li:hover {
        background: #3eaee9;
        /*background: linear-gradient(top, #4f5964 0%, #5f6975 40%);
        background: -moz-linear-gradient(top, #4f5964 0%, #5f6975 40%);
        background: -webkit-linear-gradient(top, #4f5964 0%,#5f6975 40%);*/
    }
        #headermenu ul li:hover a {
            color: #fff;
        }

    #headermenu ul li a {
        display: block; 
        padding: 15px 63.9px;
        color: #552f01; 
        text-decoration: none;
    }   
#headermenu ul ul {
    background: #f69b58; 
    border-radius: 0px; 
    padding: 0;
    position: absolute; 
    top: 100%;
}
    #headermenu ul ul li {
        float: none; 
        /*border-top: 1px solid #6b727c;
        border-bottom: 1px solid #575f6a;*/
        position: relative;
    }
        #headermenu ul ul li a {
            padding: 15px 63.9px;
            color: #fff;
        }   
            #headermenu ul ul li a:hover {
                background: #3eaee9;
            }   
    #headermenu ul ul ul {
        position: absolute; 
        left: 100%; 
        top:0;
    }

列表：

<ul id="menu">
                        <li><a href="#">Home</a></li>
                        <li><a href="#">Town Office</a>
                            <ul class="submenu">
                                <li><a href="#">Sub Menu 1</a></li>
                                <li><a href="#">Sub Menu 2</a></li>
                                <li><a href="#">Sub Menu 3</a>
                                    <ul class="submenu">
                                        <li><a href="#">SubMenu1</a></li>
                                        <li><a href="#">SubMenu2</a></li>
                                        <li><a href="#">SubMenu3</a></li>
                                        <li><a href="#">SubMenu4</a></li>
                                    </ul>
                                </li>
                                <li><a href="#">Sub Menu 4</a></li>
                            </ul>
                        </li>
                        <li ><a href="#">Business</a>
                            <ul class="submenu">
                                <li><a href="#">Sub Menu 1</a></li>
                                <li><a href="#">Sub Menu 2</a></li>
                                <li><a href="#">Sub Menu 3</a></li>
                                <li><a href="#">Sub Menu 4</a></li>
                            </ul>
                        </li>
                        <li ><a href="#">Residents</a>
                            <ul class="submenu">
                                <li><a href="#">Sub Menu 1</a></li>
                                <li><a href="#">Sub Menu 2</a></li>
                                <li><a href="#">Sub Menu 3</a></li>
                                <li><a href="#">Sub Menu 4</a></li>
                            </ul>
                        </li>
                        <li ><a href="#">Tourists</a>
                            <ul class="submenu">
                                <li><a href="#">Sub Menu 1</a></li>
                                <li><a href="#">Sub Menu 2</a></li>
                                <li><a href="#">Sub Menu 3</a></li>
                                <li><a href="#">Sub Menu 4</a></li>
                            </ul>
                        </li>
                    </ul>

使用这种方法...感谢任何帮助...是什么导致了图像中黑色圆圈中的多余空间