青函隧道开通于1988年3月11日,至今已整整20年了。目前,仍然保持着世界最长海底隧道(53.85km)的纪录,因此值得纪念。早在青函隧道通车的两年前(主隧道贯通时),日本集邮界便发行了纪念封(其纪念邮戳见图1),它是最早的青函隧道纪念邮品。在青函隧道通车当日,邮政部首先发行了轻津海峡客运轮渡(即联络船)尾日纪念封,为轻津海峡客运划上了句号。由于尾日纪念封比首日封发行数量少,所以极受欢迎(见图2)。日本铁 The Green Tunnel was opened on March 11, 1988 and has been for 20 years. At present, the longest underwater tunnel in the world (53.85km) still holds the record, so it is worth commemoration. As early as two years ago when the Green Tunnel was opened to traffic (when the main tunnel was passing through), the Japanese philatelic circles issued a souvenir cover (the commemorative postmark is shown in Figure 1). It was the earliest Seikan Tunnel memorial postage. On the opening day of the Green Lane Tunnel, the Ministry of Post first issued a day-long commemorative seal of the Qingyun Strait passenger ferry (ie, the liaison vessel), marking the end of the light passenger ferry for the Light Sea. It is very popular as the day commemoration covers a smaller number of first day covers (see Figure 2). Japanese iron