In this paper, a statistic study of the occurrence rate of spread-F＇s starting time observed at Hainan station was carried out by use of DPS-4 ionosonde data from February 2002 to December 2007 during the declining phase of the 23rd solar cycle under the conditions of magnetic disturbed and quiet respectively. Based on the spread F observations at Hainan ionosphere sounding station, the starting time statistics of various types of spread F are distinguished into Frequency type Spread F （FSF）, Range type Spread F （RSF）, Mixed type Spread F （MSF） and Strong range type SpreadF （SSF）. Results show that both on magnetic disturbed and quiet nights, the total occurrence rate of starting time of MSF is the highest. MSF performs as the most active one, FSF and SSF are secondary ones, and RSF is the least active one. MSF＇s starting time is mostly around midnight, while FSF＇s starting time falls into the post-midnight and SSF＇s starting time is pre-midnight. It is noticed that there is some difference in the starting time of MSF under magnetic disturbed and quiet nights. During magnetic quiet conditions, MSF tends to appear earlier than midnight and on magnetic disturbed nights it appears later. There is some correlation between the starting times of range and strong range types with solar activity. In the years of higher solar activity such as 2002, 2003, the occurrence rate of both types of spread F＇s starting time is higher in the time period of 20：00 LT--22：00 LT and 22：00 LT-24：00 LT under magnetic quiet nights than the one under magnetic disturbed nights, while in the years of lower solar activity such as 2005--2007, the occurrence rate of both types of spread F＇s starting time is higher in the time period of 00：00LT-02：00LT and 04：00LT-06：00LT during magnetic disturbed nights than the one under magnetic quiet nights. It is hoped that these results in this work is helpful for the study of morphology and mechanism of different type of spread-F.%利用2002年2月至2007年12月（第23太阳活动周的下降段）近6年的海南DPS-4型电离层测高仪探测数据，对磁扰和磁静夜晚期间扩展F起始时间出现率进行统计研究．结合海南电离层观测站所观测到的扩展F类型，将扩展F区分为频率型、区域型、混合型和强区域型，分别进行统计分析．结果表明，无论磁扰还是磁静夜晚，混合型扩展F起始时间总出现率最高，最为活跃，其次为频率型和强区域型扩展F，最不活跃的是区域型扩展F；无论在磁扰还是在磁静夜晚条件下，混合扩展F起始时间主要围绕在午夜前后，且磁静时更多地起始于午夜前，而磁扰时则倾向于延至午夜后，频率型扩展F在午夜后较高，而强区域型扩展F则在午夜前较高．在本次太阳活动下降阶段，强区域型与区域型扩展F的起始时间出现率逐年与太阳活动呈现一定的相关性．所得结果有助于分析不同类型扩展F在形态和机制方面的差异．
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