At nine o'clock August 30, the Fourth China-Japan Conference on Number Theory opened at Shandong University Academic Center(Weihai). Professor Jianya Liu and professor Shigeru Kanemitsu preside over the openning ceremony. The Fourth China-Japan Conference on Number Theory closed successfully on September 3, 2006 at Shandong University Academic Center(Weihai). A photo of all the participants at the gate of the Academic Center is ready for you to download. We hope this photo will bring to you wonderful memories. Date: August 30-September 3, 2006 Venue: Shandong University Academic Center (Weihai) Advisory Committee: Tao Zhan, Shandong University, China Organizing Committee: Shlgeru Kanemitsu, Kinki University, Japan Jianya Liu, Shandong University, China Guest Speakers: K. Alladi, University of Florida, USA V. N. Chubarikov, Moscow State University, Russia W. Kohnen, Universitaet Heidelberg, Germany A. Schinzel, Polish Academy of Sciences, Poland I. Shparllnski, Macquarie University, Australia Daqing Wan, University of Michigan, USA Yangbo Ye, University of Iowa, USA Shouwu Zhang, Columbia University, USA Plenary Speakers: Shigeki Akiyama, Niigata University, Japan Takashi Aoki, Kinki University, Japan Tianxin Cai, Zhejiang University, China Yonggao Chen, Nanjing Normal University, China YoungJu Choie, Pohang University of Science and Technology Chaohua Jia, The Chinese Academy of Sciences, China Yoshiyuki Kitaoka, Meijo University, Japan Yuk-Kam Lau, The University of Hongkong,HongKong Zhiguo Liu, East China Normal University K. Matsumoto, Nagoya University, Japan K. Miyakek, Waseda University, Japan Loo Murata, Meljl-Gakuln University, Japan K. Matsumto, Nagoya University, Japan K. Miyake, Waseda University, Japan Y. Nakai, Yamanashi University, Japan Xiumin Ren, Shandong University, China Masaki Sudo, Seiki University, Japan Zhiwei Sun, Nanjing University, China Y. Tanigawa, Nagoya University, Japan H. Tsukada, Kinki University, Japan I. Wakabayashi, Seikei University, Japan Tlanze Wang, Henan University, China Honggang Xia, Shandong University, China Wenguang Zhai, Shandong Normal University, China Wenpeng Zhang, Northwest University, China Short Communications: Kentaro Lhara, Kinki University, Japan T. K. Kobayashi, Gifu University, Japan Hailong Li, Weinan Teacher's College, China Guangshi Lv, Shandong University, China Masayuki Toda, Kinki University, Japan Yuan Yi, Xi'an Jiaotong University, China Deyu Zhang, Shandong University, China Supported by JSPS, NSFC, and Shandong University