The threecomponent coefficients of section model of YouCha Bridge were obtained by using two fivecomponent balances.And the threedimensional aerostatic stability of YouCha Bridge was analyzed based on the modified increment and innerouter iteration method implemented in ANSYS.It is indicated that the aerostatic stability of YouCha Bridge with spatial main cables is more excellent compared with those of suspension bridges which have two parallel main cables.A full aeroelastic model with geometrical scale of 1:90.35 was designed and used to experimentally determine the wind velocity inducing aerostatic divergence in smooth wind.And it is found that the critical wind velocity for attendant bridge is higher than the design wind velocity.