Chinese Acad Sci, Inst High Energy Phys, Key Lab Cosm Ray & High Energy Astrophys, Beijing 100039, Peoples R China
; Shandong Univ, Dept Phys, Jinan 250100, Peoples R China
; Yunnan Univ, Dept Phys, Kunming 650091, Peoples R China
; SW Jiaotong Univ, Dept Phys, Chengdu 610031, Peoples R China
; Tibet Unit, Dept Math & Phys, Lhasa 85000, Peoples R China
A lot of data has been accumulated with Tibet II and HD AS array operated successfully since October of 1995 and 1996, respectivley. The preliminary results of searching for steady TeV gamma ray emissions from Crab Nebula with these data were presented in this paper. Analysis shows that the accumulative excess events of steady 3TeV gamma ray emissions from Crab Nebula was increasing stably and the statistical significance reached 3.2 sigma, whereas no statistical significant evidence of steady 10TeV and 30TeV gamma ray emissions was found.