The threecomponent coefficients of section model of YouCha Bridge were obtained by using two fivecomponent balances.And the threedimensional aerostatic stability of YouCha Bridge was analyzed based on the modified increment and innerouter iteration method implemented in ANSYS.It is indicated that the aerostatic stability of YouCha Bridge with spatial main cables is more excellent compared with those of suspension bridges which have two parallel main cables.A full aeroelastic 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.