NOVELTY - Preparing rod-shaped nano silicon dioxide hydrosol comprises e.g. diluting spherical nano silicon dioxide hydrosol, adding aqueous solution of lanthanum nitrate or terbium nitrate, adjusting the molar ratio, adsorbing the spherical hydrosol particles on lanthanum ion or terbium ions, adjusting pH of hydrosol, adsorbing lanthanum ions or terbium ions, generating surface positive charged rod shaped lanthanum hydroxide or terbium trihydroxide and gathering of the spherical nano silicon dioxide particles on the positively charged rod shaped lanthanum hydroxide or terbium trihydroxide.    USE - The method is useful for preparing rod-shaped nano silicon dioxide hydrosol and the hydrosol is useful as solar glass antireflective coating liquid for improving durability and light transmittance of the solar glass (all claimed).    ADVANTAGE - The film coating has smooth and compact formation, good durability, wear resistance and adhesion property, and does not crack while tempering.    DETAILED DESCRIPTION - Preparing rod-shaped nano silicon dioxide hydrosol comprises (i) diluting spherical nano silicon dioxide hydrosol to a concentration of mass percent of 3-4 wt.%, adding aqueous solution of lanthanum nitrate or terbium nitrate as crystallization catalyst, adjusting the molar ratio of the catalyst and silicon dioxide to 0.001-0.005:1, stirring continuously for 0.5-2 hours to adsorb all spherical nano silicon dioxide hydrosol particles on lanthanum ion or terbium ions, (ii) adjusting the pH of spherical nano silicon dioxide hydrosol to 8-8.5 with 2% concentration of sodium hydroxide solution, adsorbing lanthanum ions or terbium ions by in-situ hydrolysis and generating surface positive charged rod shaped lanthanum hydroxide or terbium trihydroxide, (iii) carrying out hydrothermal treatment of adsorbed rod shaped lanthanum hydroxide or terbium trihydroxide spherical nano silicon dioxide hydrosol at 70-103 degrees C for 1-36 hours, concentrating the sol simultaneously by evaporation of water, gathering of spherical nano silicon dioxide particles on the positively charged rod shaped lanthanum hydroxide or terbium trihydroxide and crystallizing to obtain 4.5-5.5 wt.% rod-shaped nano silicon dioxide hydrosol with core of rod shaped lanthanum hydroxide or terbium trihydroxide nano particles of alkaline pH 8-8.5, and (iv) removing sodium ions from the alkaline silicon dioxide hydrosol through strong acid cation exchange resin column and adding 0.001-0.01 wt.% salicylic acid as acidity stabilizer and fungicide to obtain rod-shaped nano silicon dioxide hydrosol of acidic pH 1.8-2.5, where the diameter of the rod shaped particles is 20-30 nm, the length of the rod shaped particles is 40-100 nm and the shelf-stability at room temperature is 12 months. An INDEPENDENT CLAIM is also included for use of rod-shaped nano silicon dioxide hydrosol as solar glass antireflective coating liquid for improving durability and light transmittance of the solar glass, comprising (i) filtering rod-shaped nano silicon dioxide hydrosol, adding into three roll coater, attaching uniformly on the coating roller, adjusting the coater rotating speed and controlling the wet film thickness at 1500-2000 nm, (ii)coating with the rod-shaped nano silicon dioxide hydrosol roller on a clean, dry solar cell glass samples, segmenting by heat curing for 3-6 minutes at 80-150 degrees C to obtain pan-blue purple solar coated glass, (iii) optimally adjusting the three roll coater coating process parameters to control the dry film thickness at 140-180 nm on the solar coated glass and measuring the glass transmittance before and after coating respectively 91.4-91.6% and 94.2-94.7%, and (iv) tempering the solar cell coated glass samples by processing at 500-720 degrees C in a steel furnace for 3-6 minutes and sintering the film layer on the glass surface to obtain the film coated glass transmittance of 94.5-95%, pencil hardness of 6H and durability of IEC 61215 standards.